Baen and other stores won't have had the same power that Rowling has though. Amazon, b&n and the rest _want_ the potter books on their store and have been willing to compromise with a buy and link setup.
I doubt they'll do that for anyone other than the top selling authors though unless they decide to offer an api that ensures customers who find the books on amazon are tracked through the purchase on an outside store to ensure amazon get their %. Whether that's in place now or whether amazon and the other stores are getting nothing out of it other than the ability to say look we have HP, who knows.
That said, even without the account linking, I'm glad a top selling author has taken this step. Baen and others may have been doing DRM free (or watermarked) for some time, but there's been a huge lack of what some consider the "mainstream" authors from following.
Perhaps if they see the light that selling DRM free works, it will remove the publisher insistence on other stores to apply DRM which then makes it very apparent that any remaining stores are only applying it as a means of control and vendor lock-in.
I really don't think they could have done much better with the setup. Price is always going to be an issue regardless of DRM.
Perhaps my only gripe is why they didn't allow anyone to buy any language version they want. Might be a rights issue, but it's a shame they didn't solve it to allow people in the US who want the UK version the ability to do so without hoop jumping and vice-versa. In a way I wish it was more like games and movies where you buy once then get to change the language setting
