Formerly the domain of B-list actors and fading stars, appearing on the boob tube has recently become de rigueur for big name celebs. From Naomi Campbell to Britney Spears to Lindsay Lohan, TV has been all about the guest appearance this past year, and it doesn't look like it will be changing anytime soon. In between caring for five-month-old Harlow and filming her new reality TV series, Nicole Richie will appear in an episode of Chuck this fall. According to People.com, the executive producer Josh Schwartz says that, "Nicole auditioned for the part and was very funny." Meanwhile, Mary-Kate Olsen — who guest-starred on the series Weeds earlier this year, to critical acclaim — has signed on to appear on Samantha Who? "She showed up alone, ready to work, is great on set and is serious about the job," Executive Producer Don Todd says. And while it's unclear whether these performances will be award-worthy, the top 10 finalists for this year's Emmy Award for comedy and drama were announced this morning. Among the shows in the running for the prestigious TV award are Curb Your Enthusiasm, Flight of the Conchords, The Office, Ugly Betty, Weeds, Grey's Anatomy, Mad Men, and The Tudors. No word yet on whether Victoria Beckham will win for her acting turn on Ugly Betty last season.