It seems SharePoint 2010 gives a nice new way to say exactly what versions of the binaries are installed on any given server in your farm, this is a great enhancement from 2007 which effectively required a Windows Explorer properties check at times to be absolutely sure that all the servers had been updated!
Find it in Central Admin by;
- Open Central Admin go to Upgrade and Migration
- Select Check product and path installation status
You should see something like the following:
Specifically if you scroll down you will see the project server section under each server in the farm, and in my case you can see the RTM version number plus the KB2394322 (October 2010 CU).
FYI that SQL method still can come in handy (when migrating for instance) so if you’re not familiar with it here it is:
SELECT * FROM dbo.Versions
Not exactly as much detail as the above method, but it does confirm what version server your databases should belong to.