Some interesting speculation, via AllThingsD
If the new rules mean that all in-app purchasing must be vended through Apple and the App Store, my guess is that Amazon’s solution will be to drop the Kindle app [for iOS] altogether.
I know what you’re thinking: That’s just crazy!
Well, no, it isn’t.
Amazon has been working on Kindle for the Web, which has been in beta testing since last September. At the moment, you can only preview the first chapter from select titles on Amazon, but according to the Kindle for the Web page, full text is coming soon.