Oh also also? NO time travel in the next one at all. Publically stated by the writers I seem to remember, last week.
Yay! Really guys, you've set your new continuity and are free to make the new canon... let's not fuck with it any more.
Though, what I've heard (besides rumors of bringing Shatner back) is that they're thinking of having Khan Noonian Singh in the next film. Guys, you've got a practically-brand-new universe to make your own; why not tell some new stories in it?