An update for Exchange 2010 SP1 has just released and can be downloaded at: Exchange 2010 SP1 Update Rollup 7 Download.
This will take you Exchange version up to 14.1.421.0
For a description of all the included fixes, see KB 2743248
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.