There's a interesting case for an MMO to let the past be the past and have new characters start somewhat more "current".
At the same time it seems kind of crazy to toss all of the 2.X content out...but 3.0 was said to have a 2.0-like amount of content.

I would not be surprised if 3.0 again started everyone on the Main Story at the same point and that a new city in the expansion also function as a new starter city. That is ishguard would not be a starter city but perhaps some Au Ra center. New players start where their classes/jobs are, like before, but have some new starter main story. Then the new-player and old-player stories would then converge rather quickly.