Here's just a quick thought: Apple's new iPod touch is Apple's measured response to Microsoft's UMPC, a.k.a. Origami PCs. A similar sentiment seems to be ringing over at C|Net — although their post is a speculation before the iPod event of Sep. 5.
True, the primary purpose of iPod touch is still music playing. It will do that nicely, just as well as Classic, Nano and Shuffle varieties from the same family. But with WiFi and pretty much full power of Mac OSX behind it (and assuming that current iPhone hacks still work) it can be made to be much more than a music player/portable web browser.
A small totally non-scientific Apples to oran^H^H^H^H oops HTC Advantage comparison:
|iPod touch||HTC Advantage|
|Screen||3.5", 480x320||5", 800x600|
|Memory||16GB||8GB + Mini-SD|
|Battery||22h audio / 5h video||5-6h talk time, 300h standby|
Conclusion: iPod is three times lighter and can likely be made to be able to handle many things HTC Advantage does.
Ok, that part above is a troll, sure. But the point is that as before, by making a few measured steps, Apple may well be entering Microsoft's turf — and it'll likely be able to bit it there, if it sees a potential.