Maybe her advisers wisely convinced her of the problems of DRM – it doesn’t prevent piracy. And as the last movie hits theaters, Rowling needs a way to keep her brand going. eBooks are the next logical step. Even if she loses some revenue to piracy, she’ll still make a lot from the people who will buy them. I’d also expect many special deals, like the entire series as one purchase, or enhanced ebooks that link to pivotal scenes in the movie.
The real question is will this be the start of a trend of big name authors bypassing eBook stores such as Amazon and Barnes and Noble and making their own online mini-bookstores.