This afternoon Apple released yet another update for iTunes. You can visit the iTunes website here and download the update now. Otherwise, your system should prompt you to do an automatic update within the next few hours.
Apple's stated that patch will contain some “important bug fixes” as well as a fix to an issue some users have had with Apple device verification. No more details have been released, but it's likely we'll have patch notes within the next couple of days. UPDATE: Pre Owners, if you want to remain able to sync up to iTunes do not download this update. Apparently it breaks Pre syncing'