Microsoft, EU Reach Antitrust Accord
Agreed. The agreement between the EU and Microsoft states that they just have to provide all the same API's publically that they use internally. There is nothing about legacy support.
Best DNS Service With API Access?
I am surprised nobody I have seen mentions GoDaddy. They don't have a API that I know of, but they have a copy feature that allows you to copy setting(s) from one domain to all the domains. Makes mass updates very easy, and their DNS is rock solid and fast. Plus they are free if you have a GoDaddy account.