The Exchange Team silently released RU7 for Exchange Server 2010 Service Pack 1 (KB2743248). This update raises Exchange 2010 version number to 14.1.421.0.
Note that update rollups are cumulative, i.e. they contain fixes released in earlier update rollups for the same product level (RTM, SPx). This means you don’t need to install previous update rollups during a fresh installation but can start with the latest rollup available right away.
As with any Hotfix, Rollup or Service Pack, I’d recommend to thoroughly test this rollup in a test and acceptance environment first, prior to implementing it in production. For the correct procedure on how to update DAG members, check here.
You can download Exchange 2010 SP1 Rollup 7 here.