From Blizzard Entertainment:
The BlizzCon 2010 Fan Art, Original Song, and Movie contests have begun! To enter, simply submit your original Warcraft, StarCraft, or Diablo-themed work before September 27. We have over $25,000 worth of prizes to give away between these and our Dance and Costume contests on Friday night at BlizzCon, and winning entries will be showcased live at this year's show.
Head over to the Fan Art, Original Song, and Movie contest pages to see the submission requirements, read the official rules, and check out the prizes. Information and online sign-ups for the BlizzCon 2010 Dance and Costume contests will be coming soon, so keep an eye on BlizzCon.com for details.