Companies like Amazon, B&N, and now Apple, are trying to recreate the success of the Apple/iPod/iTunes trifecta.
I just don't think that's going to happen. Already there are many sources for e-books that do not force the use of a particular reader-device.
http://www.mobipocket.com/en/HomePage/default.asp?Language=ENhttp://www.fictionwise.com/http://www.feedbooks.com/http://www.baen.com/http://www.ereader.com/http://www.randomhouse.com/delrey/ebooks/http://us.penguingroup.com/http://us.macmillan.com/Honorable mention:
http://www.gutenberg.org/