From the absolutely awesome Japanese trailer I've seen for the game, it looks like some of the older generation Pokemon will be present, as Arcanine, Lucario and Seviper (I'm sure among others that people saw) made appearances on the protagonist's and the new-style Team Plasma's ranks.
As for a specific team I'd be using, I'm not really all that sure... assuming that we'll be starting with Unova's Starters, I'll probably go with my safe-bet of either Snivy or Oshawott; sadly leaving Tepig as the only Starter Pokemon I've never actually used. (which is a shame, since I really like his basic form) As for the rest, I'll keep things quiet for now, though it would be nice to be able to use some of our favourites from previous Generations alongside our Unova favourites.
But as with everything, we'll have to wait and see. I could be a little outdated on all my information about BW2, but I honestly haven't been keeping up with it all, as I did with BW.