There's a Vault Boy bobblehead, a nearly 100-paged concept art book with commentary and a behind-the-scenes "Making of Fallout 3" DVD.
GameStop have listed the details on the Collector's Edition on their site and it carries an October 7th release date. Previously Pete Hines of Bethesda has said publicly that "until you see something official from us on when the game will be out, take any date you see from anyone with large grains of salt."
The game has been slated for an autumn 2008 release so October could be the post-apocalyptic month for Fallout 3.
Clickto visit the GameStop Fallout 3 Collector's Edition page.