I got my tp2 the other day, and it irritated me that internet sharing wasn't an option when I plugged it into my pc. Of course, it's because it's disabled by Verizon. I poked around the registry and found this:
HKLM\SOFTWARE\HTC\USBToPCPopUP\OnlyTwoChoice
Edit this dword to 0, default is 1. Soft reset & you'll have internet sharing in the popup.
If it's been posted before, sorry, just ignore my 'discovery'.
I've never had to enable it before because i used to use custom roms. I got tired of all the bugs, etc, etc.....