Microsoft isn't standing still on Windows Mobile, though whoever WinMo's leadership were were inept and visionless.
My guess is that Zune HD is just a trial balloon (albeit one that will be supported for years).
Windows Mobile 7 will likely be the Zune HD Phone - and based on comments from recent Microsoft interviews about not wanting to have multiple app stores, Microsoft is seeing what works with Zune HD and how to best tweak it for usability before WinMo 7 is done and the Zune HD Phone is released.
That's probably why the Zune HD isn't outside of the US (that's right, isn't it?) - rather than spin up a world-wide product launch for a device type that is nearing the end of its tenure (really - phones will subsume PMPs), release the PMP in MS' biggest and friendliest market, see what works and tweak as needed for the world-wide Zune HD Phone release.
THEN comes the unified app store.
...all of which will *undoubtedly* be arriving in 2010.
Oh, and WinMo 7 is a 'rewrite' of the OS, branched some time ago - WinMo 6.5 isn't a direct parent to WinMo 7.







