An update for Exchange 2010 SP2 has just released and can be downloaded at: Exchange 2010 SP2 Update Rollup 4 Download.
This will take you Exchange version up to 14.2.318.2
For a description of all the included fixes, see KB 2706690
For those of you running DAGs, please see the following article: Applying Updates to Exchange 2010 SP1 and SP2
If you are running third party products (like anti-virus, etc), it is important that you disable them before updating.
More information can be found on the Exchange Team Blog site.