Last December I spent two days in Paris doing some HD-DVD technical training put on by Microsoft. It's a long story but the idea is to do some work for a friend that has a fledgling media company.
The training wasn't great as it mixed high-level talks and low-level talks without linking them very well. One day was spent on the VC-1 codec - not my area but interesting none-the-less. The other day was spent on covering the interactive layer. Very interesting but not much more was covered than you can find in the HD-DVD Interactivey Jumpstart Package. Overall, I like the programming model.
My biggest disappointment is that they didn't give out copies of the HDi specification and it turns out you can't really do a lot unless you have that spec. It's the only complete programming documentation. The kicker is that they charge several hundred dollars for it. It seems pretty stupid to me when they're fighting an adoption war. Obviously, the grass roots level isn't important to the consortium.
At the end of the second day, they spent a couple of hours showing off various HD-DVD movies projected on a proper cinema-sized screen. Awesome. It was just as good or better than a real cinema. It surprised me that it scaled that well. I don't know what projector they used but it was worth about $20,000 USD.
I have no stake in the Blu-ray vs HD-DVD battle and don't really care which one wins. I just want to see consensus and a cheap DVD-burner for whatever format wins. It would be nice to see Blu-ray drop java and use the HDi interactivity layer (as proposed by Hewitt-Packard). Besides interactivity, there's really not a huge difference between them.