It might not seem like a direct assault, but it's got to be in the threat matrix for the big booksellers... Catherine Holahan's coverage is peripherally interesting Google Download: No iTunes for Books (on BusinessWeek.com), but if I think Google still doesn't get it if they think that I'm going to pay for books that I can't read in a disconnected fashion.

The online-only reading option is the equivalent of DRM for audio -- and a lot of music producers are starting to understand that DRM is a sales-limiting technology, not a profit protector. My fear is that book publishers will lag even further behind... *big sigh*