The Dawnguard expansion to The Elder Scrolls V: Skyrim is set for release on Xbox 360 on June 26th, Bethesda confirmed today. It will cost 1600 Microsoft Points ($20).
Xbox 360 users can get Dawnguard in English next Tuesday, but speakers of other European languages will have to wait a few more weeks. French, Italian, German, and Spanish versions of Skyrim's v1.6 patch will arrive next week, and the Dawnguard DLC itself will launch in those languages in mid-July.
Bethesda has been running a limited beta for the past ten days. Those who got in get the DLC free, but everyone else has to pay 1600 Microsoft Points ($20). Dawnguard is the first Skyrim DLC; this one and the next piece of content are both exclusive to Xbox 360 users for at least one month, so English-speaking PS3 and PC players won't see Dawnguard until the end of July at the earliest.
Until then, check out our E3 preview of Dawnguard.