I bought the retail (full) version of TruePianos.  If I bring up the standalone player I get all the additional piano models.  If I add the TruePianos softsynth via the browser of the supplied track template I get the version that came with Sonar X3 which only has one piano model.
 
What do I need to do to make Sonar aware of the retail upgrade?
 
Thanks!

The full version should show in your VST list as TruePianos, while the bundled one shows as "TruePianos Cakewalk" or somesuch.
 
If you're not seeing both, make sure the DLL for the full TruePianos is in your scan path in Plugin Manager, and run a manual scan.
 

Got it!  Thanks.