In fact, American Dad! has been given the go-ahead for the 2008-09 season as well. (I think they did it early to make sure they would have enough new episodes written just in case the reported Writers Guild of America strike happens and ends up dragging on for a while.)
One thing worries me, though: once football season is over, the show is moving to 7:30 (so Fox can air
Terminator 2 1/2 The Sarah Connor Chronicles on Sundays at 9:00, and 7:30 is still considered "family-friendly" as far as the FCC is concerned. Hopefully they won't have to tone it down too much.