I can see how the organization is limited, but yeah, I usually just have a queue of 3-5 unread books. I've only had it for 3 years, though, and that's not a long-enough time frame for me to re-read something.
I haven't found the Kindle to be of much use for tech books and journals: it would need to be at least A4-sized and much sharper (and probably color) for that.
What I would appreciate is better within-book search, and more functional "X-Ray" (that's actually available for more than 1 book in 10).