Same. Series 1 and 2 both have 17 Special NPC's in them. If they did 4 series, 17 x 4 is 68, and add that to 333 (villagers in NL), equals 401. So just take out a special NPC no one cares about and you'll have a perfect 4 series of 100 cards. Though they did add Carrie into HHD who wasn't in NL, so then that would mean 334 villagers - but they might take some villagers from NL out anyway. But yea, 4 series definitely seems like a good number. I also think this because the first series is green - releasing in July, which is Summer in Japan - then series 2 is orange - releasing in September, which is Fall in Japan - so I guess series 3 will be white/blue and release in the Winter, and series 4 will be a different shade of green (or pink for cherry blossoms) and release in the Spring.
There's still Zipper, Pete, Lloid, Pelly, Phyllis, Gulliver [sailor], Gulliver [space], Gracie, Cyrus, Franklin, Blathers, Celeste, Brewster, Katrina, Copper [classic], Booker [classic], Copper, Booker, Tortimer [classic], Nook [classic], Pave, Frillard, Wisp, Kaitlin, Grams, Leilani, Leif, Serena, Mabel, Jingle, Wendell, Rover and Snowman - and whoever else i'm forgetting, which is 33 more specials for the game, and we already have 34 confirmed, plus an approximate 333 villagers, and 34 + 33 + 333 is 400 so...
But like I said before, with Carrie, they could just be bringing back older characters to replace unimportant characters like classic Copper/Booker, space Gulliver, Snowman, Kaitlin, Serena, Frillard and Wisp (who didn't appear in NL, except for the Snowman, but he's boring), so they can get rid of those specials but still maintain an even 400 character cards by adding in the older characters like Carrie to replace them.