Microsoft has released Update Rollup 1 for Excherver 2010 SP3 today. The update is now available on Microsoft download center.
As usual, this update contains number of reported issues and internally found issues since the introduction of SP3.
MS has also pointed out one known issue for installing and uninstalling this version of update, and provided with the work around. However, at present there is no plan for correcting as it may further delay the release of Update Rollup 1. The issue and workaround are stated below,
You cannot install or uninstall Update Rollup 1 for Exchange Server 2010 SP3 on a computer that is running the double-byte character set (DBCS) version of Windows Server 2012 if the language preference for non-Unicode programs is set to the default language. To work around this issue, you must first change this setting. To do this, follow these steps:
After you successfully install or uninstall Update Rollup 1, revert this language setting, as appropriate.