After claiming first place for her first two weeks as anchor of the CBS Evening News, Katie Couric slipped to second place last week, 500,000 viewers behind Bryan Williams' NBC Nightly News. Her audience was down 24 percent from her first week, while Nightly News was up 15 percent and ABC's World News with Charles Gibson was up 10 percent. The NBC newscast posted a 5.7 rating and a 12 share; CBS, a 5.5/11; and ABC, a 5.4/11. Particularly worrisome for CBS may be the fact that Couric's audience dwindled each night. Although her newscast placed second on Monday through Wednesday, it fell to third on Thursday and Friday. NBC Universal CEO Bob Wright suggested Monday that NBC might have considered Couric to replace Tom Brokaw when he retired last year but that "she never really raised her hand to go in that direction." Meanwhile, Elizabeth Vargas, who stepped down as anchor of ABC's World News to have a child, has told the Philadelphia Inquirer that she plans to "do everything I can to get back into a nightly chair" in a year or two.