Curse the idiot(s) who invented emulators. If they didn't exist, then I'd never play Pokémon Black and White. And Kyurem with new Formes? That's something I didn't expect... They probably suspected that we would think that they'd make Pokémon Grey, and then they go and make B&W2! From what I've read on Google or some other site, though, there is a site for Pokémon Grey, apparently, so maybe they're going to make it sometime in the future after they finished B&W2.
No, they're sequels. Same Pokemon, same region, maybe even the same characters... sounds about as creative as the title!
If there are new characters I'd be surprised. If they only change the character sprites, then I'm not going to be that surprised.
I'm okay with this
Maybe I'm missing something but the first two didn't appear to have any way to go back and fight old trainers/gym leaders after beating them, so I've been at kind of a loss about what to do since clearing out all the routes. Even if GF simply take Black & White's base and improve it that should make for something good, and really the series is already broken competitively so I have little care for that part anymore.
Pity that old trainers/gym leaders can't be rebattled (save for some trainers, such as those in Nimbasa's stadiums, the Battle Subway, and the eighth Badge's town, where a triple/rotation battle can be done). Basically, the only thing I do is train all my Pokémon to Level 100, take the Battle Subway on (my Pokémon should know pretty good moves when they are Level 100) and try not to cheat. I already cheated by making my Pikachu able to use Ice Beam and Frost Breath. I just hope that B&W2 will have some more new stuff than just Kyurem's Black and White Formes.