My prediction for iOS 7 is that we'll see a huge visible change to the user interface, that will be immediately noticeable in that it will be minimalistic, flat and free of skeuomorphic design elements. The home screen will be completely customizable with new elements or widgets that can convey information about notifications and cloud services.
There's little doubt in my mind that Apple will announce the iRadio streaming music service now that a Sony deal has been inked. Now Apple has signed deals with the big three in music; Sony, Universal and Warner.
Appel will introduce at WWDC a huge and significant update to Maps and Siri, including APIs and applications that will span the entire product line. That’s right, we can expect Maps and Siri not only on iOS devices, but also on your Mac!