Seth Scoen, an EFF (Electronic Frontier Foundation) staff technologist, has an interesting blog post in which he analyzes some of the arguments surrounding DRM, Apple's role and how DRM affects the market in more ways than simply locking down content. He also hopes to remind those who have gone astray from the meat of the topic that getting caught up in the Mac vs. PC (and Apple vs. Microsoft) debates in the DRM world only serves to muddy the issue, much like many political debates get too caught up in 'Democrat vs. Republican' rivalry.
One of the more important arguments that Seth examines in terms of DRM as a whole and how it affects market competition is that of 'it's the record labels, not Apple who are to blame for the use of DRM'. Seth cites an EFF post from May, 2004 in which their own Fred von Lohmann wrote about his chance to ask the iTMS head lawyer as to whether Apple would stop using DRM if the record labels
Seth's post offers some interesting perspective on these DRM arguments, and it refreshingly delves deeper than the "Apple's solution is terrible which means you should use Microsoft's" banter. Check it out.