So: the Chameleon Bar, also known as the Adaptive Status Bar, in iOS 6. Remember that conspiracy theory which has Spielberg employed by the U.S. Government to make films about friendly extraterrestrials to prepare us all and soften the blow for when they eventually admit they are real? No? Well never mind, it's not that relevant. Prediction: the chameleon bar is Apple's way of preparing us and smoothing the way for a change in aspect ratio in the new iPhone.
What better way to adapt old apps to the new size, then to give them the choice of expanding vertically, or staying at their current size with an extra stays area at the top, subtly skinned to match the app.
I promise I won't delete this in October when I'm proved completely wrong.