The EMC issue is fixed by following http://msexchangeteam.com/archive/2010/02/04/453946.aspx :
If the WSMan module entry is missing from the global modules section of the C:WindowsSystem32InetsrvconfigApplicationHost.config file, as follows:
<globalModules>
<add name="WSMan" image="C:Windowssystem32wsmsvc.dll" />
For some reason SP1 installer stripped this line. Adding it back in and restarting the Default Web Site in IIS Admin solved that issue for us.
I'd also recommend a reboot after updating Mailbox servers, though a restart of the Windows Search (Exchange) service will suffice. Otherwise you may get reports of "corrupt index" trying to switch the Active node for DAG databases.