I've just installed a new server with ePO 4.0 with patch 2 and it's managing and deploying to clients succesfully except in one regard.
If I try and set an exclusion for files that are "Protected by Windows File Protection" in a On-Access Default Processes Policy it doesn't take. I add the option to the list and press save, but then when I re-examing it, it has gone. All other exclusions for patttern and file type remain. The policy exclusions are being pushed out to the clients except for this one.
According to this KB article, Patch 2 does contain the new extensions, but for some reason they didn't automatically install. I was able to install them manually based on their location described here.