Here’s one to watch: a true start to the late-night passing of the guard, this time at CBS. Among tonight’s guests on this new edition of Late Show, current host David Letterman says hello to future host Stephen Colbert. And I’d stay tuned, afterward, for The Late Late Show with Craig Ferguson. Ferguson will have seen a preview feed of Letterman’s taping just before taping his own Monday night show – and is just unpredictable enough to comment on it, if he’s so inclined.