From what I know so far…
Is that BC-Outland will still be accessible to go through for you leveling torture needs, however, when you finish Pandaria and are ready to go to WoD-Draenor you will be sent there via some sort of… I’m not sure how they explained this during the Blizzcon lore panel, I’ll have to do more research on it, but I think via a similar way we go back in time for any CoT (Caverns of Time) dungeon.
I’ll keep you posted if I find more solid information.
Have they explained how going to and from regular, exploded ‘present-day’ Outland is going to work story-wise? I haven’t figured that part out yet; since I have characters who live there, it’s kind of a vital thing.
They’re still trying to figure out how to have both draenor and outland available at level cap.