I meant "the next generation of ebook devices," not the people reading them. The first device that offers that is going to be able to make serious inroads on the Kindle, if they don't absolutely botch the rest of it. I don't think *anything* lets people download-and-read-ebooks other than those through the official branded store portal.

I can see problems with it--once you allow download-and-open ability, you're facing virus issues--but a device that could only run a limited set of filetypes should be able to get around that. If MegaKillerWorm.exe has been disguised as GreatEbook.epub, the epub reader just won't deal with; it shows a blank page or error message.