[nekokami]

I'd probably pick up one or two. Prisoner of Azkaban, at least (still my favorite). Maybe Deathly Hallows, just to make the point. Depending on the cost, I probably won't be able to re-purchase all of them -- I paid a premium to get the last three volumes on recycled paper in hardcover, and I'm not feeling especially generous toward the franchise at the moment.

Now that Mobi has a decryption method available, it won't bother me any if they are only available in that format.

Edit: if they have a discounted set of all 7, I might go for that, depending on the price. Since they're all out now in paper, it would make sense to offer them this way, and by the time they're likely to have ebooks ready, they'll all be available in paperback, so hopefully there will be no silly hardcover pricing involved.