One of the reasons Apple may be holding back on subscription services is that they may want to make a major play for bundling various media into channels: Rather than subscribing to the NYTimes, you could subscribe to "US leading newspapers" and get the NYTimes, WSJ, Washington Times, for one low price, kind of like an album, or in cable television lingo, a channel.
What's cool is that with Apple's iTunes store being multi-media, the channels could include books, podcasts, apps, music, movies and tv in a single channel.
They could have a Parenthood channel, a SciFi channel, a Self-Help (Lifehacker?) channel, a Cooking channel, a Gaming channel, a Womens channel, a MAKE channel, etc etc.
I don't know that they could ever quite pull it off, or whether they could pull it off in a way that would be advantageous to them, but think of the customer lock-in that could achieve. Sure Android might have all the same popular apps, but you can't purchase them for one low price along with related TV/Music/books/podcasts/magazine/newspapers etc.
Steve Jobs could very well usurp Howard Stern for the title King of All Media.