Though the iPod hardware is more than capable of playing WMA, and iTunes appears to be prepared to be capable of playing it (iTunes’ icon resources house icons for WMA and OGG, among others), Apple will exclude the functionality until a court order forces their hand. That’s my prediction.
Apple already considers itself to be the Microsoft of music downloads… and what could be more Microsoft–like than being sued to anti–competitive behavoir? Their aim in the music arena is, obviously, to sell iPods; and since their iPod/iTunes/iTMS combo is so exclusory to competing products, enabling support for the one DRM format that every other online music store is using (WMA) would be counter–productive. But one day… one day when they’ve thoroughly annihilated the competition on the hardware, software, and music–store front (I’m talking thoroughly), the competition will sue. It’s the way the world works; Apple doesn’t want to open up the iPod for competitors to knock them from their perch, and the law says that just ain’t fair.
The law is, after all, an ass. But so is the corporate personality.