Didn't catch the AS premiere bump this summer or check the board, did you?
No, they are working on season 4 as we speak. From Brendon and Jon Schnepp, the episodes are going back to 15 minute ones this season. As per AS's bump, the season will premiere April 15, 2012 and be only 12 episodes.
Yes, that is little over half as long as the past three seasons. (Seasons 1 & 2 were 20 15-minute episodes, and season 3 was 10 30-minute episodes.)
But Brendon has hinted at a movie after season 4, which may be the last season. NOTHING is confirmed on this, but Brendon has hinted he'd like to do a movie- and continue with Dethklok CDs- since the first season.
~ Dethklok Roadie #149 (female) ~ Red Tie Coven # 1 ~ Toki's Candygirl #2 ~ S.H.O.T.T.S. #51 ~ Dethklok Minute Reporter ~