Everyone above who says that the author missed the point because Apple's profit model is based on the iPod rather than iTunes, misses the point.
Yes, Apple has a cash cow right now with the iPod. However, the big money (even bigger than the iPod) is to be the de-facto standard for DRM and content distribution. People buy iPods once every couple of years, but they buy content every day.
I can't tell you Apple's plans, but I would think they would sacrifice a portion of their iPod sales in order to be the one everybody has to pay whenever a piece of entertainment gets downloaded.
Besides, it's not just about what Apple can win, it's about keeping Microsoft from controlling the next phase of the Internet and taking all the profits. If Plays For Sure becomes the standard, how popular will Apple's products be?
Want to Marginalize the iPod? Ask Steve Jobs How!