I've said before--and I stand by the statement--that Apple doesn't have a lot of wiggle-room here without disrupting their retail channel for iTunes cards, which (IMHO) is a really important competitive advantage they have over, say, Android.
Having the retail credit channel is the equivalent of the importance of having prepay options for cell phones vs postpay. Many people don't want to put CC info in iTunes or they simply want to give gift cards to kids.
What Apple should do is make such a service optional. If it's compelling, people will use it. I also believe that for some people this will be compelling because they then don't have to deal with billing and all the infrastructure (payment gateways, receipts, accounts departments and so forth) that that entails.
Forcing it down people's throats is another matter entirely.
It's still unclear how this will relate to the Kindle, which is really what interests me, as it is a mix of subscriptions and single-purchase publications, all of which are purchased outside of the App Store.
Part of the problem is that there is an internal inconsistency in play. You can subscribe to the Wall Street Journal Web edition and use that on Safari on your iPad just fine. Why should the WSJ app that gives you access to that same content be any different?
You could sell an app on the App Store for $10 and Apple would get their $3 cut. Give a free version away and offer a $10 in-app upgrade and Apple still gets their $3 cut. From Apple's perspective, why are subscriptions any different?
I guess Apple are seeing this as people making money off their platform so they should get a cut. That position has superficial attractions but quickly breaks down if you go deeper.
To me it's a lot like the ISPs who want to charge Netflix or Google for all the bandwidth they use, which is nothing more than double-dipping. The customer pays for the bandwidth. What they use that bandwidth for should be immaterial to the ISP.
Personally I think Apple makes enough money from selling the devices, the App Store and iTunes that just nickel-and-diming people who produce material users subscribe to to the point of excluding such content from the device is really not in their interest or the user's interest.
Not having Grooveshark on my iPhone/iPad is a problem (that predates this). Losing other music services will be a problem. Losing the Kindle will be a HUGE problem.