I CAN CONFIRM I GOT MY VGX-XL3 TO RUN IN 1080P!!!!!!!
I have a westinghouse 43' 1080p, and when I go to the options menu it says 1920x1080p 60 hz!!!
This is what I did:
Updated to the newest nvidia drivers, updated to Vista Ultimate (probably not necessary, but I wanted remote desktop).
Then there is a program that sony installs called Resolution, run the setup utlity. Switch the 1080 option to 1920x1080 instead of 1780 or whatever the other option is.
Now run the Resolution utlity, and select 1080!!!!! BOOM, FULL 1080P!!!!
Happy 1080Pin! GO SONY!