Word came down Late Thursday that David Letterman will be retiring from his TV show next year, 2015 when his current contract expires. Splitsider.com is reporting that Dave made the announcement at the taping of Thursday's show. Mike Mills from REM was at the taping and broke the news on Twitter.

CNN's Brian Stelter added this:

i have been watching Dave for as long as I can remember. I followed him from NBC to CBS. His style has always spoken to me; sarcastic, silly and a little bit grumpy. That's how I like it. He didn't suffer fools lightly or just kiss up to the celebs. He always seemed to be on the audience's side. He will be missed, but he leaves behind a broadcasting legacy that defined a generation of humor.