Let's look at this logically, as Bulbamander has stated: we saw models and textures of AC in Mario Kart 8, and now we're seeing legitimate, familiar assets in a main franchise spin-off game for the Wii U. I sincerely believe they just wanted to give us a taste of what is to come. I mean, have you seen the details in the trailer? We have dirt paths with shapes, and we have a new main character. This stuff is in HD, too.
Trust me when I say that I, too, share in the disappointment that we're not getting a new AC in the next year, but I am optimistic as this is a good sign that they're not just jerking around in their studios with earplugs in, ignoring the very people who are keeping their company afloat.
I feel like comparing New Leaf to a possible Wii U version of the game will be like comparing Mario Kart 7 to Mario Kart 8; they have the same core mechanics but there are a lot of differences and a lot of tweaks and improvements since 7 was released.
And, since when has HD been a bad thing? Who here can say they hate the New Leaf engine enough to turn it down on the Wii U?
I will admit, I haven't been in this fandom for the long haul, New Leaf is my first Animal Crossing experience, but looking back and researching the previous games for previous consoles, there hasn't been a lot of innovation as far as the core game mechanics and the general look of the game go. You could make an argument that Wild World and New Leaf run the same engine if you lay them side by side, without looking in depth at what is actually inside each game; you could say "New Leaf is an "HD" version of Wild World!", but we know that it isn't because we know with certainty what's inside of each game as individuals. I think that the same will go for the Wii U version (whenever it will come out), that there will be a lot of little tweaks and improvements that will make the game even more of a blast to play, even if it does end up looking or feeling a lot like New Leaf does at present.
You have to assume that since we didn't get an announcement for a new main game at E3 this year that there is going to be another whole year (or more!) for the developers to be making changes and adjustments. We don't even know if what's been shown in amiibo Festival is going to remotely look like what is in the official game, and the same can be said for the Mario Kart 8 track, and even NintendoLand (though, I doubt those assets will be used for anything but NintendoLand).
In the end, it's all speculation and I am pretty tired of people being pessimistic and hateful toward Nintendo for not one, but two, spin-off titles for a well beloved franchise. We didn't get exactly what we wanted, but at least they didn't leave us hanging with nothing at all; although, at this point, I'm wondering if we'd all be better off for it.
Ok I'm with you on this but I'm gonna add a few more things to add light on the situation.
Firstly, let's take a look back on AC3DS, as it was known at the time. Forgive me if I'm wrong, but when we first learned of this game, it was back at E3 in 2010, where we got some short footage, and a few screenshots. Here's a look at some of the screenshots;
Screenshot #1: The trees are drastically different to what they are in the final. They look more willow-like than oak-like.
Screenshot #2: The text box is different, and Rosie's house is completely different than her usual Lovely themed attire - which probably means that they'd only modelled a few furniture items and just shoved some in her house to make it look nice. This can be backed up by the fact she has a music player and a couch in her house, which probably would've been developed/ported early to get the music and sitting features in the game so it wouldn't crash when these things were attempted. It's also possible the couch can't even be sat on, and the music player is just for show and doesn't actually play music.
Screenshot #3: Public Works Projects have cobblestone around the bottom of them
If anything, this shows that the game was pretty early in development. Not only that, but this game was announced in 2010, and
didn't release in the west until 2013, three years after it's announcement. And if I remember correctly, Isabelle hadn't even been designed at this point, because they hadn't even created the mayor mechanic, because they stated in an interview that the mayor aspect of the game was added late into the games development. I'd say the game was probably only around 10-20% complete here, which is pretty early to show off a game. Remember, this game was shown off in 2010, which is 2 years after City Folk released, the E3 that just passed was 2 years since New Leaf released, and going off what we've seen here, if (which I think there is) a Wii U title in development, chances are it's either early in development, or Nintendo has learned from their mistakes and chose not to announce it as early as they did with New Leaf - because the fans went into meltdown not knowing a stable release date.
Come E3 2011, and the majority of these things are still in the game - the only thing that seems to have been removed was the cobblestone from PWP's, and the game still didn't even have an official name at this point (also worth noting, though minor, but at both E3 2010 and 2011 the flowers are a lot different than what they are in the final) - the dock is even different, which may suggest the island hadn't even been developed, or even thought of at this point - the text box had changed once again, and like Rosie, Bunnie's house doesn't really resemble what her usual house attire looks like, though the general principals within her house in the final are present;
Come E3 2012, and the game was seemingly missing, probably because they announced the game way too early given their development progress and came across a bump in the road, which ended up delaying the game. If anything, these three occurrences at E3 show that New Leaf was poorly planned (thankfully it turned into a great game). I think I can speak for a lot of people when I say I really don't want this to happen again with an AC title, people were going crazy.
My next point is to give hope to people who are flipping out because "it wasn't announced at E3". I'm sure there are more games, but off the top of my head, three main series titles, Pokemon X and Y, Pokemon Omega Ruby and Alpha Sapphire, and Majora's Mask 3D were not revealed at E3. Arguably, Pokemon and Zelda are much bigger franchises than Animal Crossing, so there really isn't a reason for them not to reveal them at E3, because they would've hyped up fans a lot. I can understand why X and Y weren't at E3, because they were a new generation, slated for an October 2013 release, and if they announced it at E3 then they would've lost around 5 months pre-release time to hype up fans, but as for the other two titles, there's no reason why they couldn't have announced them at E3. ORAS were announced on May 7th, which is only about a month before E3, now yes, the whole "they wanted a longer pre-release period to release information" thing from X and Y can be applied here, but here's the thing, they didn't actually reveal any information until E3 2014. They gave us like 5 second of footage of Groudon and Kyogre jumping out of the water like a week after it's announcement, but once that was done, we go nothing until E3. So there is literally no reason why they couldn't have waited another month to reveal these games and have them announced at E3 and created a lot more hype. Because waiting a month for information on a game we knew nothing about was pretty boring.
Same for Majora's Mask. Now here, you can say that because it was a port of the N64 version, it didn't take that long to develop, but Nitendo has actually said that they started on Majora's Mask 3D not long after they finished Ocarina of Time 3D, which released first on June 16th, 2011. Majora's Mask 3DS was revealed November 2014, and released February 2015, and for those who are too lazy to do math,
that's basically a 3 year, 5 month development period where they said nothing about the game, and didn't even reveal it, and revealed the game 3 months before it was set to release - and initially, they actually said the game would come out in spring 2015, but they actually pushed the game forward to winter 2015, as it came out in February.
Basically my point here is that just because a game isn't revealed at E3, doesn't mean you should lose all hope, because there are things called Nintendo Directs, where they actually reveal main series games.
The next thing is for people who have lost all hope of it ever coming to the Wii U. Now, I probably would have, too, but remember as I said before, it's only been 2 years since New Leaf, Nintendo revealed "AC3DS" 2 years after City Folk released, but it was still in early stages of development, and probably could've gone without revealing it.
So now we talk about Zelda U. The Zelda franchise (as mentioned before), is a lot larger than the Animal Crossing franchise. Zelda U was set to release Holiday 2015, then was announced it wouldn't be at E3 2015, and now has been pushed back to at least the second half of 2016, which I'm going to go ahead and assume the game is coming out in Q3 2016 at earliest, and will probably end up being the 2016 holiday title. They've also said that Zelda U will still release on the Wii U, and isn't going to be shelved for the NX, and I think the same applies for AC Wii U. Like I said, Zelda is much bigger than AC, and if Nintendo truly believe Zelda can sell well on the Wii U, what have they got to lose releasing an Animal Crossing on the Wii U as well. If it had been announced that Zelda U was in fact dropped form the Wii U, and to release on the NX, then yes, I would say AC Wii U is gone, but it isn't, so for anyone saying the Wii U will be "dead" next year, think again because if it were, Nintendo wouldn't be releasing one of their biggest franchises on the Wii U late next year. Also, again like AC3DS, if I remember correctly, Zelda U was first revealed at E3 2012, and wasn't mentioned again until E3 2014, and judging by the game play footage from the E3 2012 trailer, the game is 100% completely different to what we're getting now, which further more concretes the idea that Nintendo can work on games for a long time without revealing them, because they probably just revealed that trailer with a closer release date in mind, but for whatever reason, was delayed (which is probably what happened with AC3DS, too).
And my final point, which isn't really relevant to much of what I've said above, so if you're too lazy to read don't bother reading this part - but in regards to amiibo Festival, I honestly think this was just Nintendo's way of trying to please fans, but having it backfire. As I've said before, I believe they're working on a main series AC title for the Wii U, but given the NL development treatment, that didn't want to reveal it until it was more concrete, so instead they decided to reveal a spin-off title instead, hoping it would make fans happy, but it didn't. Looking back to when Happy Home Designer was first revealed (April 1st, 2014), on the amiibo cards they showed in the direct, they still have the die roll numbers, and rock, paper, scissors hands on the cards, which are obviously for the cards compatibility for amiibo Festival. Since they were present on the cards, it's pretty obvious that at the time they announced HHD, they very easily could've announced amiibo Festival, but didn't - and we're probably keeping it for an E3 reveal to tie fans over for a Wii U AC title until they finally got around to being happy with AC Wii U's development, so they could announce it with out having to change the release window 50 times. They also wouldn't have a main series game and a spin-off announced at the same time, because it would hurt sales. Yes, I know they've done this before with Pokemon, but like I've said before, Pokemon is bigger than AC. If they actually revealed both amiibo Festival and AC Wii U, or even HHD and AC Wii U, it's guarantee that the spin off title would get less sales than the Wii U title, because a lot of fans would just be like 'why would I buy a spin off when I can buy a main series title? Such a waste of money".
Anyway, congrats if you bothered to read all of that, but TL;DR - I do think AC Wii U is in development, and I really see no reason to panic over it yet. If they don't reveal AC Wii U by E3 2016, then yes, you can start to freak out, and if it hasn't been revealed by the end of 2016, then I'll say it's a lost cause, but right now, there really isn't any reason for them not to release it on the Wii U.