> But Stripe hasn't nailed it and Braintree couldn't nail the "immediate sign up" outside of the US so I too will wait to hear if it's all that much different.
Correction: Braintree hasn't nailed it even inside US, despite reports otherwise. Even though you can sign up and get started with a developer account immediately, there is a human underwriter who looks at your account and activates production. This process might take lesser time now, but its not automated (like Stripe) and some people might get rejected on the way.
This step is the key value proposition for me. If Braintree or Paymill doesn't work like that, then they are not comparable to Stripe.
I'm not sure why Microsoft doesn't put it up on the App Store. They will probably get a lot less customer information, but things would be so convenient. Apple will stand to make a cut, but then there are several companies which sell both on the web as well as the App Store - why not do that.
Adobe was hesitant at first too. They brought several smaller apps to the App Store at first, then followed by some big ones.
However that is planned for mid this year.