The late-night talk shows are due to resume live competition tonight (Wednesday), with David Letterman expected to take over as the ratings leader. Letterman's company, Worldwide Pants, negotiated a separate deal with the Writers Guild of America last week, which will allow him to return to the air with a full complement of writers. Leno will return sans writers, since his program is produced by NBC, a struck company. Letterman will also have the additional advantage of being able to include celebrities who are members of the Screen Actors Guild, which has urged its members to shun other talk shows. As a result, he has been able to book Robin Williams as his first guest on his CBS TV show tonight; Leno's guest will be Republican presidential hopeful Mike Huckabee. (Before the deal with the WGA was signed, Letterman had said that Donald Trump, who is not a SAG member, would be tonight's guest; he has been bumped to Friday.) All eyes at the networks and at the ad agencies are likely to be on ratings results later this week. The New York Times quoted a representative of Worldwide Pants as suggesting that more people may initially tune in to view the struck shows to "check out the potential train wrecks."