Blizzard released a new minor patch today as per the following news item.

New Minor Patch

We have released a minor patch for World of Warcraft. This small update addresses certain issues in Blackwing Lair and includes some improvements to the Macintosh client. To read the full list of changes, take a look at the patch notes here.

For an explanation of the different types of updates that World of Warcraft can receive, please read our Patch FAQ.