Well a generation so far has been over 3 years long and this is only a little over 2 years. I don't see them announcing a game that will not release until 2014 right now. Someone mentioned they are about done with the league in the anime but they can cover the stuff in B/W2, much like they did the battle fronteir for Emerald.
I can go out on limb, not that far and say it is probably the Wii U version of Coliseum/Battle Revolution going to be announce since there isn't one for Gen 5 yet. I will be going out further on the limb and say they will almost totally by-pass physical and release it digitally and in almost all market this quarter. I think it will be a quick release window because it seems that all markets are getting a form of the announcement on Tuesday. As pointed out elsewhere they have all the 3D models done, for the Pokedex on the 3DS. And I don't see a Battle Revolution type game taking up that much space, even if they flesh it out.
