Pretty much agree with the points said so far, mainly:
1. New Game+
2. No more new pokemon, for a while at least.
I mean, don't get me wrong. Before I played Black and just looked at designs on Serebii I wasn't too keen to say the least. Then after actually playing the game I found myself actually liking a lot of the Gen 5 Pokedex. Point I'm trying to make is, yes I don't want new pokemon for a while, but that isn't because of nostalgia glasses or anything like that. It's simply because I'd like time for the latest batch, and some of the old'uns I guess, to sink in and be.. I dunno, appreciated? Like Don Savik says, giving the ones they have depth, working on quality rather than quantity.
CrimsonBlaze said:
Also, new evolutions to existing Pokemon in the Pokedex (come on, we need an evolved from of Rapidash to be a flaming flying Pegasus).
Cannot agree more with this. Something that bugs me, is that instead of going with what would appear to be a natural, sensible evolution like the one you mentioned, instead they'll slap a whole new badge to it. You could say it doesn't make much difference in the end. Whether a flamng flying Pegasus is it's own entity entirely or a later form of Ponyta/Rapidash doesn't matter, it'll still function the same, look the same, etc etc. Yeah, you'd be right, I wouldn't argue against you. But on a personal level, I'd prefer they work with what they have instead of churning out new stuff like there's no tomorrow. Goes back to the previous point: giving depth to what they have.
Apart from that I'd just like a deeper story. (I know it's a kids game, but B/W took a surprising step forward that I hope they continue)
Oh. And justified legendaries. But I won't go into that one too much, don't want to (potentially) start arguments.