Brendan also posts interesting comments in HD Photo: Not Too Shabby:
"You know that we here at fnord have a thing for file formats. Don't ask why, we just do. Well, there's a new format coming down the pipe, and it's HD Photo. It looks like the format to rule them all, so of course it must come from Microsoft. And that's why it pains me to say this: HD Photo actually looks really great..."
read the rest in HD Photo: Not Too Shabby.
Update: Brendan later recommended HDR Labs as well as How to Create Professional HDR Images by Ryan McGinnis.
Aravind Krishnaswamy also has an article that might also be useful: Creating high dynamic range images with Adobe Photoshop.
Update 2: podcast Technology Today talks to Tim Grey of Microsoft on JPEG XR