A lot of details were left up in the air when Pottermore was announced a few weeks back. Today Google posted about their new relationship with Pottermore, and they answered a couple of the questions I still pondered.
Google just announced that they were the new partner of Pottermore. But don't get too worried; you'll still buy the ebooks from Pottermore (so the promise of DRM free ebooks still stands). What this means is that if you like, you can transfer your newly purchased HP ebooks to your personal library in the Google eBookstore. Google will also be the payment processor for Pottermore.
I have to say that I'm both surprised and not surprised. I thought Overdrive would run the Pottermore ebookstore (they're building it, after all). On the other hand, this doesn't surprise me because Pottermore will require support for making a heck of a lot of sales transactions at once. Google can do that, no problem.