Looks like this might be useful...
The Beside The Cursor Revit Build Checker has been updated to support Revit 2010 products when they are available. No need to launch Revit and search for the build number...just launch my script to get a report on installed versions of Revit from Release 9.1 through 2010.
Also works with 64 bit Windows XP and Vista.
Also works with Revit MEP and Revit Structures.