Buying music right to your player? Sounds GREAT!
* There goes your battery life
* And/or the thing gets bulkier and heavier for battery and antenna
* You probably have to pay something for the communications service involved (rather than just using your home ISP)
* You can't browse and sort results, with album art, columns of details, etc., on a tiny screen as well as you can on a computer's large screen
* You can't enter artist/title names to shop for on a handheld device as easily as you can with a real keyboard
* You can't manage and edit and organize your collection as well on a handheld device as you can with a mouse--unless you have a stylus adding bulk and ready to be lost (but no matter how bulky, the screen will still be smaller than iTunes on a computer)
* Your new music is now arriving in two places (assuming you still buy CDs or use download services)--rather than the simplicity of always sending new music directly to your computer which is your master library
* What about burning CDs?
* More complexity is not always a good addition to your music experience
* Would the quality be reduced, or would the arrival of the file just be slow?
* Is having to worry about finding a signal and signal strength and interruptions a good thing for shopping?
* You still have to plug in to charge anyway, which takes longer than synching your latest downloads
* Can't you wait until you get home? Is this really a "problem" consumers want solved?
* It still won't have Apple ease-of-use (or style or mindshare)
* Nearly every time poor Microsoft gets press exposure for it, the iPod and iTunes will be mentioned too--free mindshare for the competitor, and often in the tone of Microsoft copying Apple and playing catch-up (not the best kind or PR in the Vista vs. Leopard age)
* It will either be designed separately from the software and service (which puts it at a disadvantage compared to the well-integrated iPod + iTunes) or else it will be competing with services from Microsoft's allies
* The hardware will be competing with Microsoft's allies regardless.
* If you have to have DRM, I'd rather mine didn't come from Microsoft.
* It probably won't run on Mac, yet Microsoft will talk about "choice."
Otherwise, it sounds great
Even if Apple came out with such a service/device, many of the same problems would still apply.
But we don't know what will really be released: something else--like streaming satellite radio--I can see having its place. Still too bulky for me, but a streaming digital music subscription would have its uses. Maybe Microsoft is creating Sirius or FM with more choice? (Or with less?)