Skyrim - Dawnguard DLC Released for X360

Bethesda has released the first DLC, Dawnguard, for TESV: Skyrim. For the next 30 days it is only available for the X360 - link to the download for X360
http://marketplace.xbox.com/en-US/Product/The-Elder-Scrolls-V-Skyrim-Dawnguard/8ab49c69-b2d8-4055-99c8-a941655f5de8

Dawnguard™ is the first official game add-on for The Elder Scrolls V: Skyrim® - the 2011 Game of the Year. The Vampire Lord Harkon has returned to power. By using the Elder Scrolls, he seeks to do the unthinkable - to end the sun itself. Will you join the ancient order of the Dawnguard and stop him? Or will you become a Vampire Lord yourself? Featuring an all new faction questline and locations, the ultimate choice will be yours.

In this thread at the official forums you can how to start the Dawnguard DLC - link to the thread: http://forums.bethsoft.com/topic/1387092-starting-dawnguard/