I think that "ebook" is different from "book", and that's ok. :) I also think it would be super cool if the NYT Ebook list dealt with every ebook, but I'm not sure that will happen. Well, at least not right away.

Still. As a reader, I will always define "book-length" as "something that takes more than an hour to read" unless said item is a journal article, in which case I will call it a journal article. :D