Just thinking aloud: Is there any other game series that has been released with so few changes so many times?
The obvious answer is Pokemon, but upon closer examination, there's been far more changes in the five Pokemon games over the last 15 years than the five Animal Crossing games in the last 10. Wild World was just Population Growing with hair and hats added and NES games and decent framerate removed, City Folk was just Wild World with all the new stuff moved to a different place and with the ability to have different patterns on the front, back, and sleeves of your shirt. And I don't know how much difference there was between AF and AF+, but AF+ was pretty much ported directly to the GCN. This looks like it might have pants customization finally, and with the action on the top screen, the bottom screen might always be the inventory screen like it really should have been in Wild World. The mayor thing does leave some hope for some real changes, but even then, I probably won't want it (though I'll probably end up buying it anyway).
The only change I really want is major streamlining. Everything takes way too long to do in City Folk. I'd also like it if I could just import my original GCN town and just play on that. I think it just made such a big impact on me eight years ago, when I was twelve, that every other town I've ever played just feels like a cheap imitation of it. Also because it was a three-level town, which apparently was kind of rare? I don't know, I think I heard that.
Let me bring in my good old Acorn, and then just put in a bridge over the river in that one acre on the middle level (Tortimer came and offered to build a bridge twice, and both times it was like five feet away from a bridge that was already there. I said yes because I wasn't sure if he'd offer again if I said no, and just assumed he'd keep coming back and building more bridges forever until he eventually got one in the right place, but clearly that is not the case now), make me the mayor of that town (without a whole bunch more micromanagement getting added in), give everyone some new dialog while also keeping all the old dialog, and put that on the 3DS maybe with Wii-level graphics but more importantly at 60 FPS, with the inventory screen always on the bottom screen, with tools not taking up slots in the inventory and with not having to put away my fishing pole when I talk to someone and pull it back out when they're done (I can talk to them when they have their fishing poles out, seriously), and I'd be happy. Also make the weeds not be so obnoxious, or add a lawnmower. And stop making me water flowers.
Bringing back the NES games would be nice too, but we all know that's never happening again, as great a feature as it would be to be able to access your VC purchases from there after tying your accounts together on Club Nintendo (I mean, seriously, how hard would that be? Not very.).