Well it looks like we’re in for a repeat of that skirmish, as Letterman and newest “Tonight Show” host Conan O’Brien go head-to-head to earn the hearts (and eyes) of viewers.

So far, O’Brien has been holding his own, winning the time slot seven of his first eight nights. But his audience, which was way up for his first night, has been steadily falling off and Letterman edged ahead with Tuesday night’s show, earning a 3.4 rating/8 share vs. a 2.9 rating/7 share.

Despite their pronouncement anointing O’Brien “the new king of late night,” it looks like NBC execs are getting nervous, bumping Tuesday night’s scheduled guest (Norm MacDonald) for a bigger gun (Eddie Murphy).

For his part, whether it’s asked for or not, Letterman is getting a boost from some big guns of his own, with Howard Stern proclaiming “Here’s the host we wanna watch!” and Julia Roberts making it clear where she stands by quipping, “You are so much funnier than other people who talk at this time of the evening.”

Of course, Letterman’s escalating war of words with the comedy-gift-that-keeps-on-giving, Gov. Sarah Palin, probably won’t be hurting his ratings either.

Stay tuned.

Thursday, June 11
Matt Giraud – “The Ellen DeGeneres Show” – rerun
Hilary Duff, Mike Birbiglia – “The Bonnie Hunt Show” – rerun
Jonas Brothers – “Late Show with David Letterman”
Norm MacDonald, Jim Gaffigan, Neko Case – “The Tonight Show with Conan O’Brien”
Artie Lange, Blink-182 – “Jimmy Kimmel Live!”
Jay Mohr, Green Day – “Last Call with Carson Daly”

Friday, June 12
Black Eyed Peas – “The View”
Simon Cowell, Black Eyed Peas – “The Ellen DeGeneres Show” – rerun
Della Reese – “The Tavis Smiley Show”
Sarah Colonna – “Chelsea Lately” – rerun
Moby – “The Hour with George Stroumboulopoulos” – rerun
P.J. Harvey, John Parish – “Late Show with David Letterman”
Jamie Foxx, Kevin Nealon – “The Tonight Show with Conan O’Brien”
Mary J. Blige – “Late Night with Jimmy Fallon”
Paula Abdul, Todd Glass – “Jimmy Kimmel Live!” – rerun
Dane Cook – “Late Late Show with Craig Ferguson”
Foxboro Hot Tubs – “Last Call with Carson Daly”

Saturday, June 13
Norah Jones – “Austin City Limits” – rerun
Will Ferrell, Green Day – “Saturday Night Live”