Jon Lech Johansen’s DoubleTwist Ventures is selling a third-party implementation of Apple’s Fairplay rights management system (the software that makes sure that only you can use your iTunes purchases, and then only in iTunes, iPod or the upcoming iTV). What this means is that other companies will be able to sell you similarly-protected content, playable on your iPod, but without the iTunes Store as the middle-man.
I can’t imagine that this makes Apple very happy. Apple’s lawyers, on the other hand, are probably salivating.
If you line up the interested parties according to how they would align themselves in a legal battle, I have a hunch it’ll look like this:

The only company that wants Apple to be the gatekeeper is *Apple* (and Disney is obliged to play along), yet they all want to sell content for the iPod, and they want the protections Fairplay provides.
I don’t think Disney can be underestimated (few companies have been so successful in bending the law to their will), so the battle is probably more evenly matched than it looks– but I’ll still predict that the winner would be DoubleTwist.
Of course, this is through a warped view of the legal system where powerful interests matter more that the actual facts and law. You don’t know any place like that, right?