Three retailers have all listed StarCraft II for a December 3, 2008 release, but should we believe this? The short answer: NO.
Retailers often make up release dates just to keep their website updated and push pre-sales for games that have no announced date. Shacknews argues that three retailers probably wouldn't all pick the same date and that this could have some credibility.
We believe that Vivendi, the publisher, is probably giving this information to retailers and that's the reason for the shared prediction. StarCraft II does not have a release date and isn't even in beta yet. Don't expect December 3rd to be true, especially with Blizzard's track record for releases.
We could get some new information out of Blizzard's Worldwide Invitational later this week, however. Expect something on the real-time strategy game.
Side note: For some great Korean Pro-StarCraft with English commentary, check out the GOMTV Intel Classic and Star Invitational. There are over 200 videos in the back log with great commentary by Nick "Tasteless" Plott.