One of the biggest compliant I have is that you cannot link it to you YouTube account. With the new update, this is no longer a problem.
Since there is no "change log", here are what I have noticed that's new with this HTC YouTube App (apologies to the Samsung and LG lot) in my brief time of playing with it.
- Ability to sign on (and have it remember your sign on information) to your YouTube account
- view your uploads and your favourites (via the "My Account" item - weird)
- Integration with Zune Video/Music hub.
Hit up the HTC Hub and grab this YouTube app (don't search for YouTube in the marketplace) if you haven't done so already.