DRM free music increases Apple's income. a Free Software version of iTunes doesn't. There is no reason for Apple to do anything that won't increase its income.
my point in saying that is - have a supported port of iTunes on GNU/Linux and other kernels, then i would have absolutely no problem purchasing a DRM free mp3 using a version of iTunes licensed under a Free Software license. Also, they could offer open compatability standards such that other players could be used as well. They would get praise from the community for doing that more customers as well. i for one would then become a customer :-)
This is interesting.
Open question to the list :
How many people would be willing to buy DRM free mp3's from Apple, using a Free Software version of iTunes ?
Regards,
- vihan