In one of the most closely watched ratings races, NBC’s Today show topped Good Morning America last week when the ABC program had former Today star Katie Couric as guest co-host. With hyped appearances by Meredith Vieira on Monday, Sarah Palin on Tuesday, Ryan Seacrest on Wednesday and veteran host Matt Lauer announcing his new deal on Friday, Today drew 5.11 million viewers last week, up 11% from the previous week. GMA (4.90 million) got a smaller boost in viewership, up 1%. Among adults 25-54, both shows actually declined slightly. Today (2.14 million) was down 2%, GMA (1.83 million) was down 5%. GMA won Wednesday in total viewers, with the other 4 days going to Today.