> Now, if Apple has put a real DRM/Encryption in there, it would be quite another story.
I'm pretty sure iBookStore ebooks are DRM'd (same as Kindle files) (EPUB has a provision specifically for DRM, FWIW) but according to an other commenter the .ibook output of iBook Author is an epub3 book, you can just change the file extension and drop it into an ebook reader (though Apple has apparently added e.g. CSS extensions for nifty effects, which your ebook reader likely won't support).
I'm pretty sure iBookStore ebooks are DRM'd (same as Kindle files) (EPUB has a provision specifically for DRM, FWIW) but according to an other commenter the .ibook output of iBook Author is an epub3 book, you can just change the file extension and drop it into an ebook reader (though Apple has apparently added e.g. CSS extensions for nifty effects, which your ebook reader likely won't support).