It looks really cool. I wish, however, that the overall ecosystem was easier to create these things cross platform rather than per-corporation. I don't really want three or four different devices so that I can read works on iPhones, Androids, Kindles, etc. In fact I don't even want a device, I already have a browser running on a screen.
The current ecosystem has the feel of the 1990s, when corporate web sites were walled off behind the AOL domain, although I admit that today's walled gardens are much shinier than AOL ever could have been.