Three things really stood out to me when they showed that it was in 3D.
• The textures they're using are sat miles below what the 3DS is capable of.
• They may have favoured over-use of 3D, a gimmick which imo gets old fast (so, in fairness, I am somewhat biased here) over actual gameplay content.
• The previous 3D games, Colosseum and XD, allowed movement beyond four directions while they're still using 'grid'-style movement here. Seems limiting and inflexible.
Don't get me wrong - I'm not on some sort of crusade against 3D here. I just feel like, just because it's on the 3DS, they don't have to get ultra-obnoxious with it. That said, though, we've not seen enough to judge yet. I'm quietly hoping that the game switches back to the 'overhead' view if 3D is disabled. That'd just be amazing for me!
All somewhat minor issues which I'll get over and which won't stop me getting the game, though! But yeah some stuff was simply bound to change eventually because GF were just gonna run out of ideas or get stagnant and... that's not really something to complain about. I remember when people were complaining about re-usable TMs, haha.