I'm as happy as everyone to see that it's going to be possible to buy music without DRM. I've only purchased a few tracks as I regard buying with DRM as being like renting rather than buying.
This move will surely stimulate more content sales, and perhaps better, will open up the market to iPod alternatives that will play your purchased content.
The purpose of DRM is to make it hard to pass on the content, the downside is so bad (honest customers losing the ability to play stuff they paid for because they upgraded or something) that it could be that less intrusive alternatives are being sought.
The obvious one to me is content fingerprinting. Add a unique customer code to the data in the content that doesn't affect the play but can be used to trace where the copy came from. Sure, there'll be ways to strip them out in the end, but for most consumers, if they know their purchased tracks can be traced back to them it will dissuade them from "sharing".
I'm making this up, it might not be on the agenda at all, but it is possible.