Add me to the list of people who is interested only when annotation is available as well.
Though, I'm going to need more details on how it works (when they finish it of course) so it's not a definite buy yet by any means. The main thing is I'm hoping the annotations are saved as part of the PDF and not a separate bitmap image or anything of that sort, because I'd need the ability to transfer the document, with the markups, and use it on my tablet PCs as well.
Writing on epubs would be nice too, but I doubt that's going to happen.
