"What is Zune HD? Zune HD is a couple things. Number one, Zune HD is a music player with a nice music service. By the way, the same software will be available on Windows Phones and Windows PCs. You have that today on the PC, you'll see that in our phone environment as well."
Straight from Ballmer's mouth to your eyes and ears. Ballmer dropped this tasty morsel during an interview with CNET. Now of course there is no mention of WHEN, but like pocketnow.com, I believe it won't happen until the Windows Mobile 7 OS launches. Even the most powerful of the current crop of Windows Mobile devices probably would choke on a full Zune HD experience.
This is, without a question, excellent news. Microsoft desperate needs to integrate its different platforms in an intelligent way and this is absolutely one of them. I no longer use Windows Mobile (I switched to Android almost a year ago) and I was just saying today I can't see a reason I'd come back. This could be a reason. This would be a major upgrade over WMP at least!