"Finally your Libby questions will be answered," said [Carlton] Cuse, referring to the character's enigmatic — and incomplete — backstory. "No, they will not," joked [Damon] Lindelof.
The LOST producers, quoted in a TV Guide story, are clearly glad to have this all wrapped up. As are many dedicated fans.
The article also mentions:
[Harold] Perrineau (Michael) and [Cynthia] Watros (Libby) are the latest in the list of believed-dead characters who are scheduled to reappear in Season 6, including Ian Somerhalder's Boone, Dominic Monaghan's Charlie and Katey Sagal's Helen.