To me, there is a distinct movement towards a particular style and I would be very surprised if Apple were ignorant of it. It’s not ‘flat design’ per se and it’s certainly nowhere near the ‘Metro’ levels that people are suggesting they may follow, but it’s a mellowing out of the visual indicators that people need to trigger the idea of a tappable element. Why? Because this is not 2007 anymore, and we are all now fully aware of the medium and the process; we don’t need to be led garishly by the hand. There is still a sense of depth and tactility but done in a refined and suggestive way, sensitive to the changed perceptions that people have of interacting with touchscreens.
Google and Facebook have led the charge recently for throwing design resources at their iOS apps and redesigning them in a beautiful, subtle and elegant manner. The idea that either of those wouldn’t have inside information about the direction of iOS 7's UI and styling is beyond belief and we can only assume that the similar route they have taken (which doesn’t follow Google’s completely-flat Android style - that apps like any.do have done on iOS) suggests to me a direction we might expect Apple to be pushing people. One design pattern which is becoming more and more prevalent is the idea of ‘cards’ on top of a simple (usually neutral/grey) background. This is opposed to the iOS standard of information being displayed in cut-outs into the background. I believe this may have been started by Pinterest but there’s a large number of apps now using this style as a clean way of presenting information (see below - also Mailbox, Gmail and many more).