Today, Tor Books, the largest science fiction publisher in the world, announced that henceforth all of its ebooks would be completely DRM-free. This comes six weeks after an antitrust action against Tor's parent company, Macmillan USA, for price-fixing in relation to its arrangements with Apple and Amazon. Now that there is a major publisher that has gone completely DRM-free (with more to follow, I'm sure; I've had contact with very highly placed execs at two more of the big six publishers), there is suddenly a market for tools that automate the conversion and loading of ebooks from multiple formats and vendors. For example, I'd expect someone to make a browser plugin that draws a "Buy this book at BN.com" button on Amazon pages (and vice-versa), which then facilitates auto-conversion between the formats. I'd also expect BN.com to produce a "switch" toolkit for Kindle owners who want to go Nook (and vice-versa).
I know e-book adoption rates have been huge to date, but I believe we're starting to reach the point where the store-centric e-book system we have is becoming a problem: People are realizing that unless they buy all their books from one retailer, all of their e-books will never be in one library. (I am fully aware that Calibre solves this problem—I'm a big fan of Calibre—but most people just prefer not to worry with the bother of taking extra steps to emancipate their libraries.) DRM-free e-books mean that buying a book becomes as easy as hitting a button. There's none of that silly, annoying Adobe DRM hoop-jumping to go through. I expect that in six months we'll start to see that un-DRMed publishers sell more e-books than locked-in publishers.