I usually don't pay much attention to newsletters, but something caught my eye in this one.
Upcoming beta test of payment system
We are almost ready to kick off the beta for our payment system. The payment system will allow visitors to your site to use their Amazon account to pay you for any product or service. You can also offer subscriptions and controlled access to content. You will be able to verify the status of any transaction to make sure that the user has not rescinded it. We will provide you with a base-level API and you can construct your business logic on top. If you would like to be a part of this beta test, please send your request to webservices@amazon.com (webservices@amazon.com).
I've heard rumors of this for awhile, but that's cool as hell.