I read this thread initially with a bit of trepidation. Whilst it was nice to hear that J.K.R has finally understood eBooks or at least realised some people do prefer them to paper books, I was expecting the books to be rife with DRM. If the news items are true and it is just a watermark, then I know what I'm buying in October
I said years ago on here that I'd never buy the paper books as I'm pretty much eBooks only now so would either miss out on the entire series or have to borrow it from a friend. Either way J.K wouldn't have seen a penny from me. But she's picked the perfect time to release the eBooks, close enough to the release of the final film that my interest is still there for reading the books.
As for the sub-discussion of watermarks been DRM, well, I do agree they are DRM, but its a form that's about as good a compromise between the existing alternative and draconian DRM schemes and no DRM at all.
The only restriction it really imposes is on re-sale and since you're licensing the book and not supposed to resell it, it's a form of DRM that actually does what it's supposed to do and no more.
It won't prevent you using the content on the devices of your choice, editing it if you wish, reformatting and knowing you can port it to new devices in the future, making notes and so on.
Would I rather buy books totally DRM free. Yes. But if a book is only available with watermarks I don't mind buying it. The only thing that would put me off is if the watermarks are visible in any way.