Apple started to tight its control over the App store even more than before, by announcing Sony that they can't sell content - such as ebooks - in it. Apple wants their users to only be able to buy content from their own company, so rejected Sony's application which would have allowed Sony Reader Store ebooks to be bought by Apple users.

Though an iPad user does not need a Kindle to read Kindle ebooks bought from Amazon, this move might affect Amazon.com too. If Apple will continue tightening its control over the App Store, Kindle ebooks might be rejected from selling too. This changes lots of things on the market, because Apple seemed to offer more support to other companies, but it might just have been for a short period. 

What's sure is that Apple rejected Sony's Reader and, from now on, more companies might have to stop selling their content in the App Store.