First off, just because the feds are looking at a company, means very little. They do it on a regular basis when someone complains about anything. It is only making the news because it is Apple, and Apple is news. Steve Jobs sneezes and there is front page commentary. The experts have said that there is little chance of anti-trust regulations being in play here because it does not meet the criteria.
Second, this means nothing to the consumers, because it will not affect pricing of any products. Music is already priced to where Apple has the bulk share of the market. If it were not for Apple, everyone would probably be paying $1.99/track from all sources. That is what has Rhapsody and others upset, because they cannot compete with the price level Apple has set. The book and magazine sellers will determine if they want to sell on iTunes. The only difference is that if you buy from another source than iTunes, you will do it on your full computer. What is the big deal there?
Right now, Apple is using their market power to get content at a lower price than if you bought it through traditional retailers. They are doing what Wal-Mart, Amazon, etc. has failed to do. Even magazine subscriptions will be where you are able to renew them from the original vendor. They just have to pay Apple if Apple does the processing, and you cannot go to the vendors sales site directly from the app. The likely scenario is that you will sign up for a free app or an app that is part of an inititial subscription which Apple may get 30% of. After the initial subscription, when it is time to renew, you would get an e-mail saying that you can renew by going to [xxx] website. A subscription as part of a print subscription, will not be affected by Apple's policy, nor will any other purchase that is not made through iTunes. It is the same thing that happens with Amazon if you buy something through Amazon from one of their affiliate vendors. Amazon takes a cut of the profits for processing the payment and providing the site information. Surely, you do not expect them to do that for free? Remember that every app that is posted on iTunes has to go through a review process, then it costs Apple time and money to post the app, provide downloading capability, and reviews. It is not cheap, and they do not make any money off the free apps.
Apple gets a lot of attention because they are so good at what they do. The catch is, what they are doing here, is nothing new. It is a correction on a problem that was going to hurt their finances in the future, so they fixed a leaky hole in the boat.