For the first time in the history of the series, and as rumoured, a main Pokemon title is getting a sequel. We're not talking about that "perfect" version that always comes out, in this case it would presumably be Pokemon Grey, but of a full-fledged, numbered sequel. Pokemon Black and White 2 was announced on Pokemon Smash! and via Junichi Masuda's Twitter account last night.
The game(s) (depending on how you see the series) will feature new legendary Pokemon and be released for the DS in June in Japan. An English-language version is practically guaranteed because it's Pokemon..
So this leads to ask: why a sequel? My theory is that the Pokemon team are also working on 3DS and Wii U titles, and this game will tide fans over until they can talk more about them. Still, the hope is that this will be more than a quick cash-in sequel and that, actually, they'll be pretty good.