Cory is a good writer (I have enjoyed a few of his novels greatly), however, I think he is really over selling the FUD here. Sure, FairPlay is lame. I hate DRM as much as the next guy (well, unless I am standing next to Cory that is) but FairPlay is ridiculously easy to get around, even without breaking the letter of the law. Simply burn an audio CD of your purchased iTunes tracks and like magic you can do whatever you want with that CD (though this only works if you burn an audio CD). You can put it in a Walkman, you can toss it out the window, you can make thousands of copies of it (from the CD, iTunes does limit you to 7 burns of a playlist with FairPlay, though you can get around that too since the limit is based on the order of the songs), or you can even re-import the music on the CD into any format you like (Ogg anyone?).
That solves the iTunes Store lock in problem, because if you are really that passionate about moving from iTunes you'll figure this trick out. So we now know you can rid all of your iTunes audio purchases of DRM with a little time and effort but what about Cory's assertion that 'once you put music on your iPod, you can't get it off again without Apple's software?' While that is what Apple would like you to believe, once again this limitation is laughably easy to get around. There are a boatload of apps that will move stuff off of your iPod and onto your Mac (I'm a big fan of iPodRip) which are all able to function because the music folder on your iPod is simply hidden, and not really 'locked down'. Furthermore, if you're comfortable using some rudimentary Terminal commands you can even navigate to the music folder yourself and get at your music that way without spending a cent (though, I suppose in that case you would technically be using Apple's software in the form of OS X).
Cory's point, even though it is obfuscated by a slight tint of overreaction, remains valid: DRM treats consumers like thieves and really serves as nothing more than a point of contention between those willing to buy their music legally and the companies that want to sell it. The only way that we will know for certain if Steve really meant what he wrote in that letter is to wait and see. Here's hoping that the future of the iTunes Store is DRM free.