Really happy that they were able to show off a good amount of it at E3 with the limited time they usually give these games. Can't wait to play it now!
One of the developers had said the reason why they extended the release was basically to ensure longevity of gameplay, so you'd be able to play the game for a very long time. Makes it worth the wait, IMHO.
Animal Crossing was already a game that you could play for a long time (still playing New Leaf after 6 years!) But this seems like it'll be a much more gradual game and you'll have to put in so many hours to get the town you want!