SHORT CUTS

Mark Harmon has nabbed the lead role on CBS's upcoming JAG spinoff... Jerry Seinfeld will perform two shows at Caesars Palace in Las Vegas on May 2 and 3... Survivor: The Amazon was the most-watched show on TV last week with 23.2 million viewers... UPN has renewed WWE Smackdown! for an additional two years. (Please, contain your excitement.)... Steve Martin has signed on star in a remake of the 1937 ghost comedy Topper. He'll play the role originated by Cary Grant... Will & Grace's Megan Mullally will guest host Friday's Late Show with David Letterman. As reported, Dave is recovering from shingles... A retooled version of Julia Louis-Dreyfus's comedy Watching Ellie returns to NBC beginning Tuesday, April 15. It replaces the struggling A.U.S.A.