I got a Kindle a while back, and I have to confess that I've been pretty disappointed that there isn't an equivalent of Napster or The Pirate Bay for ebooks yet, as far as I can tell. But it isn't merely an issue of consolidation, it's an issue that a lot of books simply don't seem to have .pdf versions which are readily available yet. Yes, the books that you'll find in Borders often do, and a lot of popular textbooks do as well, but beyond that... I think this is a serious limitation to the appeal of e-book readers. I was able to accept that the Kindle was missing a lot of obvious features because readers are a new technology, but I find the lack of .pdf versions of the texts I want to be more problematic.
Granted, a lot of the books I can't find in .pdf versions are available from Amazon's store. But iTunes it ain't... I'm not going to seriously invest in Amazon's walled garden until the prices fall to something closer than what you'd expect of a digital copy. Ebooks need their Napster if only to pressure the publishing industry to reform.