http://online.wsj.com/article/SB1000142405274870477560457612...
As far as we know, Apple has not directly set a deadline for Amazon. In fact, there's no knew information other than the date: meaning there's still a lot of questions about the subscription rates and the actual requirements Apple will have in place.
Personally, I can't see how a 30% fee for what amounts to little more than payment processing can stand. It's one thing to charge the fee for app distribution and marketing in the store. It's another to handle on billing at which even 10% would seem rather high.
I don't see this lasting. Either publishers will charge an extra fee on iPad users and/or Apple will be taken to court for anti-trust, probably in Europe first.