Cynthia Nixon has joined the cast of 'The Big C,' starring Laura Linney as a wife/mother/teacher who gets diagnosed with terminal cancer. The Emmy-winning 'Sex and the City' alum will appear in four episodes of the series, which officially debuts on Aug. 16. Gabourey Sidibe ('Precious') and Idris Elba ('The Wire') are also slated for recurring roles [Deadline Hollywood]

More casting news after the jump.

There seems to be an epidemic of blabbermouthing going around these days. First, Vice President Joe Biden's wife Jill lets it slip on Oprah that Joe had his choice of VP or Secretary of State (snap Hillary!), then Steve Martin reveals that he and Tina Fey will be presenting together at the Oscars (so much for secret presenters), now Donny's let the cat out of the bag.

While taping The Bonnie Hunt Show, Donny Osmond announced that he's doing Dancing With the Stars, the new edition that commences in March.

Oops! See, it wasn't Donny's job to make the announcement. He was supposed to let ABC decide the right time to reveal the lineup of celebrity dancers, although whether they can dance before the show begins is debatable.