Letterman: I'll Quit Late Show in...

What will David Letterman be doing in two years? No one knows, but one thing he apparently won't be doing: hosting the Late Show. He let that little tidbit slip casually while interviewing Howard Stern last night. The clip in the gallery ends, of course, just before the comment, but Splitsider reports that later in the interview Letterman tells Stern he'll only do the Late Show for two more years. (You might not hear the announcement in this clip, but you will hear a lot of Leno-bashing from Stern.)