We’ll find out soon. The guy who became a billionaire from selling Broadcast.com to Yahoo!, then bought the Dallas Mavericks NBA team, will be a contestant on this fall’s "Dancing With the Stars." Marie Osmond, Wayne Newton and Jane Seymour are also among the celebrities who’ve signed up to exhibit their twinkle-toed abilities on ABC. For the first time, the competition will have 12 celebrities paired with professional dance partners, allowing ABC to stretch out the highly rated reality show a bit longer. Other dancing celebs announced yesterday include "Scary Spice" Melanie Brown, boxing champ Floyd Mayweather, "Sabrina Bryan of Disney Channel’s "Cheetah Girls," Indianapolis 500 champion Helio Castroneves, actress Jennie Garth of "Beverly Hills 90210" fame, model and actress Josie Maran, actor Cameron Mathison of ABC’s "All My Children" and model Albert Reed. The show kicks off with a three-day special event September 24-26, with Dolly Parton as special guest on the first Wednesday "Results Show."