Visualize a kid in an old fashioned candy shop. The kid looks at the jars of different kinds of candies, salivating and trying to figure out which candy he wants. Then when his mama finally buys him some, he likes it that much more because the anticipation has enhanced his desire for and enjoyment of the candy.
That's the way I am with New Leaf. I love watching the videos and the anticipation of it all. For me, that will make the game that much more fun when I finally have it.
But as others have said, you know yourself best. If you don't want to see "spoilers", then it would be better to avoid them.