The new cumulative updates for SharePoint Server 2010 and SharePoint foundation 2010 are ready to download:
KB 2459125 Full server package for Microsoft SharePoint Foundation 2010
KB 2459257 Full server package for SharePoint Server 2010
Further instructions and information:
After installing the packages, you may be prompted for a reboot of your Server! Please don’t forget to run the PSConfig Wizard anyway, even after reboot just to ensure that all updates has been applied completely and successful!
As usual, you can use the command line on each server in Farm: “psconfig –cmd upgrade –inplace b2b -wait”
A complete list of all published updates since Beta/RTM is found here: 2010 cube sheet
Known Issues (regressions in Dec.CU):
"You cannot create an AD DS synchronization connection ... after Dec.CU 2010 installed (KB 2490381)"
In some cases the given workaround may not help or no AD-connection at all can be created.
If so, try to recreate your UPA, do a reboot and then recreate your AD-connection.
"You cannot create an Active Directory sync connection when the NetBiosDomainNamesEnabled property is set to true".
It fails with “Unable to process create message” error.
Both of these issues have been verified as resolved in the February 2011 CU for SharePoint 2010.