While I joked earlier this month that SQL Server 2012 Service Pack 1 was released on the same day as General Availability (hey, it's Microsoft's fault since they decided to GA on April 1), this time it isn't a joke. Today Microsoft has released Cumulative Update #1 for SQL Server 2012. About half of the fixes affect the database engine. Analysis Services and Data Quality Services make up the bulk of the remainder. If you're running SQL Server 2012 now, I suggest you apply the update. This would also be a good opportunity to test the slipstream functionality in setup, to see if it automatically pulls in the CU #1 update for new installs (I'm on vacation so will try that out next week).
I've seen many people insist that they will not even think about deploying SQL Server 2012 until Service Pack 1 is available. In CU #1 there are 55 fixes currently listed, but most affect SQL Server 2008 R2 as well, so these are not issues that have anything to do with pre-SP1 jitters. But I guess some will continue to lock themselves into this old wives' tale that no software publisher could ever produce RTM code that is stable enough for prime time.
Note that some of these fixes that affect both 2012 and earlier platforms won't be available for SQL Server 2008 R2 until the next cumulative updates are released for those branches, which should be within the next two weeks (and for 2008, about 6 weeks). Though based on the code freeze for an RTM vs. a CU I suspect that some of the fixes just released for SQL Server 2012 are already in place for the earlier versions. It would be tedious to do a fix-by-fix comparison but, now that I've alluded to it, I'll probably end up doing it at some point.
The build number for SQL Server 2012 CU #1 is 11.0.2316, and you can see the following KB article:
I'll update this space when I have more information.
NOTE: If you are using Data Quality Services (DQS), please see Greg Low's blog post.