Hmm... That basically leaves Gen. V as the only solo timeline. (which is also undefined) I think if Gen. VI events happens after the BW events, but not during the BW2 events, we may get to see N. Which would be cool, in other words in the two year gap between Gen. V games is where Gen VI takes place.
Oh jeez, the Zelda timeline... !! I didn't actually know anyone else even gave the Pokemon timeline any attention so, actually, I'm kinda glad to see responses here.