Jennifer Aniston is appearing on Oprah this Monday with some big news. What that is, we don't know. But if you're thinking she'll be spilling the beans on her alleged "tell-all" book, guess again.

This promo gives away the fact that Jen has something to do with Oprah's Big Give. Producers for Oprah said Jennifer was the nicest, sweetest person, and agreed immediately to appear on the show when asked.

And Jen isn't the only A-lister to be making a cameo on the show. Jada Pinkett-Smith, Gayle King and Natalie Cole will make appearances on the April 6 episode. John Travolta will lend a hand on the April 13 show.