So, right now we're all pretty much expecting for the story to take place in a different region (N was seen in a faraway region sequel hook, yadayada), right? So let's just assume that the region this'll take place in is completely new rather than an already existing one (For the record, I'm in the Hoenn camp. But this is more interesting.)
What would the starters be? I guess it'd make sense for us to get the same ones from B/W, but I can't help but think that'd be kind of boring. Maybe they'd somehow switch it up a little. I hope for that, but it's probably most likely that we'll just be using the gen 5 starters again.
Would we just be running into B/W pokemon again? I'd be down with that, but maybe they'll get some older guys in there somehow. I guess I don't really care either way.
Would we play as the same characters from B/W? They could set up some plot so that we lost all our Pokemon from the first game and have to start all over. Maybe pull an Ash and decide to leave them all in Unova. Or we'll just be somebody different, and run into the B/W main characters in the game. How weird would it be to find them and actually have a conversation with them? Think Golden Sun 1/2 main character swap.
How would legendaries work? Obviously we'll be seeing Black and White Kyurem, but what else? There won't be any new ones to fit in there, so maybe there'll just be older legendaries placed around the region? Or maybe they'd just not have any. I doubt that, though.
This is all so unprecedented. I don't even know what to think. I can't wait to get some actual information about this.