Microsoft has released Update Rollup 1 For Exchange 2010 SP1. Few issues were raised in the forums after the release of service pack 1.
Exchange 2010 Service Pack 1 must be installed prior to installing this update rollup. Any Interim Updates (from Microsoft Support) for Exchange 2010 must be uninstalled prior to installing this update rollup.
Download the Update Rollup here
Forefront Protection for Exchange 2010 users will have to disable it using fscutility /disable as usual and enable it after the rollup installation using fscutility /enable. Information Store and Transport services will not start up without these steps.