It came down to the 11th hour, but both Variety and Hollywood Reporter's websites are saying that BL has been picked up for a 5th season. I think the negotiations had to do with ABC buying out "Life on Mars" from David E. Kelly, and in exchange, Kelley wanted at least another season of BL.
From what I've read elsewhere, it's a full-season, but ABC has the option to trim it down to 13 episodes.
Agreed. I have this very bad feeling that if it's an Aptow-inspired movie, Rogen AND Jonah Hill will get lead parts, and that can't be a great thing. The liberal use of profanity really ruins the movies he directs or produces.