Blizzard has released its first post-Wrath of the Lich King update for World of Warcraft. There are a plethora of changes, including the much-requested ability to create a Death Knight in any realm, provided you've got a level 55 character tied to your account (prior to this, you needed a level 55 on the same server).
We're not even going to try to delve any further into the patch notes. Instead, we'll kindly point you in the direction of WoW Insider for a full in-depth analysis. If for whatever reason, your auto-updater isn't working, you can download the patch via BigDownload.