By Ken Tucker
Updated June 02, 2009 at 03:43 PM EDT

David Letterman did not let the premiere of Conan O’Brien’s first Tonight Show go unmentioned:

I don’t think we’re in for all-out, late-night war — that’s so, y’know, Leno-esque. Besides, Letterman appreciates Conan’s stated admiration for Dave’s body of work. Well, Dave did say that while Conan is “a tremendous guy,” he also noted, “I think years ago, he killed a guy.” Oh, yes, I do think it’s going to get even more interesting than usual over in the house of Late Show.

Bill Cosby was Dave’s big-name guest last night, and they had a terrific conversation, including Cosby sharing a funny story about the late George Carlin.

Never count the older guys out, kids.

Did you watch Letterman? What did you think?