Kristen Bell | PetiteBell.org | Your Ultimate Kristen Bell Source

I just read that Kristen will have return as a guest on season 2 of Party Down on IGN.com webpage:

Besides Guttenberg and Lynch, other Season 2 guest stars include Kristen Bell, returning as rival caterer Uda, who is not dating Henry, along with Christopher Mintz-Plasse (Superbad), Thomas Lennon (Reno 911) and J.K. Simmons (Spider-Man). Enbom noted that David Wain (Role Models) is directing one episode, while his fellow The State alum Marino is directing the season finale.