From Zap2It.com: Chevy Chase leaving NBC's 'Community' after four seasons

As far as news go, this isn't surprising at all. Chase has been more than a little vocal about his unhappiness being on the show and his feuds with show staff have been pretty public. From a creative standpoint, his character has been tougher and tougher to incorporate into the overall storylines of the show. From a fan standpoint, he was my least favorite character. I don't think he started out as my least favorite character, but he has become it. Anyway, he's already filmed eps with the upcoming season apparently, so he'll be in the show for most of the eps...I don't know that I see Community lasting past this season what with all the behind-the-scenes turmoil on top of the lack of ratings, so I'm not sure his departure actually affects the show at all, but whatever. I just want my show back, if even for a little while. You can read the whole story here.