So what does the HD in ZuneHD stand for? Because without an adapter, it doesn't do High Definition. With an adapter you can TV-Out to a HDTV in glorious 720p. That isn't as good as your Blu-Ray player's 1080p, but it is the resolution of many HD TV stations (others are 1080i).
The 3.3 inch screen of the ZuneHD (iPod touch is 3.5 inch) can display in only 480 x 272 (the last number is the important one). That is about the same as an iPod touch (and iPhone) at 480 x 320.
The ZuneHD does have HD Radio capability. But that is HD as in Hybrid Digital. As in cramming as much content as possible into the radio frequency. If you are lucky, especially on the AM bandwidth, you will pick up higher quality radio feeds than analog.
If you don't want a smartphone that can stream Internet radio, and if you KNOW there is HD radio in your area with a station that you want to listen too (that is a lot of ifs), then the hybrid digital capability of the ZuneHD is a major plus.
The 720p to your TV is good if your XBOX, PS3 or computer is far from the right TV and you don't have a Blu-ray player with Internet capabilities. The required dock isn't pocket size, but should probably fit into a large purse.
OLED screens are awesome. The "O" is for organic. And like with food, organic is better... Oh, you want to know why? Um, ah, better contrast and uses less electricity. Better contrast is good. Extra battery life? Well, do people complain about the battery life of the iPod touch? No. People complain about the battery life of the iPhone. And the ZuneHD is not a phone.
Other details are scarce. The browser is apparently IE6 mobile. No flash player for you (not that there is one on the iPod touch).
The ZuneHD is available for under $300 dollars. But only in the USA because Microsoft doesn't like foreigners. Just to be clear: THE ZUNEHD WILL NOT BE SOLD OUTSIDE OF THE USA!