Symptoms include the inability to install rollup updates and some cmdlets not functioning properly.
The updates to avoid are:
Exchange 2010 SP3 has been released and enables support for running on Windows Server 2012. I have not yet tested it, but since Windows Server 2012 has PowerShell v3 installed, this SP should also allow PowerShell v3 to be installed on other versions of Windows Server.
I have Exchange 2010 SP3 running on Windows Server 2012 with all updates. I was playing yesterday and noticed that EMS loads by using the -version 2.0 switch. If you try to kick it over to use version 3.0, it's not happy. Don't do that!