User blog comment:Jimeee/Hearthfire confirmed as the latest add-on. Official trailer./@comment-107.5.247.181-20120830043036/@comment-3492791-20120830050711

Microsoft made a deal with Zenimax that the first two DLCs for Skyrim would be timed exclusives for the Xbox360. In return they got 2 1/2 tons of money.

Similar to Dawnguard (The first DLC) this DLC (The second DLC) will likely only be avalible to 360 users for an extended time, then later released to the other systems.