- The iPod is the leading player on the market
- The iPod only plays Apple's flavor of DRM'ed music files
- Apple is the only one providing this particular file format from its own music store
ergo Apple is trying to build a monopoly for its music store through its iPod players.
Now that could barely make sense to me ONLY if the iPod had supported WMA and Apple decided to remove it later on, to enforce some kind of shady monopoly afterwards, where people are enslaved to the iPod and you force them to use iTunes-provided AAC. As it stands, the player never played anything else than what it plays today, and it won on its own merits (or on the media hype around it, take your pick). Their was no illegal maneuvers that I can see in that.
The only thing you might say is that Apple should open up its DRM format for the sake of compatibility, so that other players can play the same files (and I don't know if there is any legal backing to that kind of demand, IANAL).