I'm one of the "voracious" readers that Charlie mentions and while I really like the Kindle DX hardware, I'm increasingly concerned at being tied into an Amazon ecosystem long term.
Baen, O'Reilly , Pragmatic Programmers and Fictionwise are some of the places I look for new books for my Kindle before Amazon these days, as they have DRM free titles.
I have an atavistic attachment to paper books, [1] but even so, I have a Kindle that I use primarily for Instapaper and, more occasionally, for out-of-copyright books. I'm reluctant to buy DRM'ed books for the same reason you are, and for the same reasons Stross articulates: no one knows what the publishing / reading landscape is going to look like in two years, let alone five, but the paper books I bought when I was 12 still work quite nicely.
[1] http://jseliger.com/2012/02/16/amazon-com-daniel-kahneman-an...