If you are going to pick on the retailers, and not the publishers, whose idea it was to use DRM in the first place, why not include Sony and other EPUB retailers such as BooksOnBoard? After all, you can't read EPUBs on Kindles, not just the other way round. Or LIT files and Adobe PDF, which BoB sell.
The DRM argument has been flogged on this forum several times
and it's getting a little irritating to see it constantly revived by people who didn't do their research before buying a device.