Less than a week after Microsoft stopped pushing out its Service Pack 2 update for Mac users with Office 2011, it's offering a patched version that should clear up the issues people experienced with Outlook. Previously, a small group of users who had installed SP2 found that they needed to rebuild their Outlook database but were unable to do so, making the software unusable. The update fixes this problem, so if any corrupted files are detected, they'll be successfully rebuilt instead of stalling Outlook. For people on SP1, it also automatically copies AppleScripts and autocorrect lists to their new location in SP2, fixing an issue that Macworld previously mentioned caused SpamSieve to stop working.
Regardless of whether you installed SP2, you should be able to run the update without problems. If SP2 is installed, you'll need to manually copy any AppleScripts and autocorrect lists (Microsoft gives instructions here) instead of having them automatically moved. That's somewhat annoying, but let's just hope there are no further problems with this version.