Same here. Can't access iTunes. Also, when I try to open the App Store all I see are the selections at the bottom but the screen is white. However, I can select Genius and view the images for the suggested apps, but clicking on any just results in a white screen again.
The problem with the App Store started earlier today when I was installing a few updated apps. Like you, I'm using an iPhone 4S with iOS 6. I've tried quitting the app and also shutting down and restarting the iPhone. I've also tried syncing with iTunes on my MacBook Pro with no success. Next step is to re-install the app, once I figure out how.
John