iOS 7 interface only shows White version - Black iOS 7 in the works?

iOS 7 as shown has a lot of white backgrounds and looks terrific with the white iPhone.

Jony and Apple are talking about "Design" vs software design being independent of hardware design - talking about the entire design as being one thing.

iOS 7 is shown EXCLUSIVELY on the white iphone at WWDC and on and in videos.

There were rumors of a heavily white iOS 7 and a heavily black, changing perhaps based on the color of the phone or the ambient light.

I believe that iOS 7 that comes with the black iPhone may utilize heavily black backgrounds with white text in most of the apps (settings, mail, calendar, etc)

After all this talk of the whole design experience and such, incorporating both hardware and software, I'm having trouble picturing this very bright white iOS 7 on a black iPhone - but having 2 versions to make the software and hardware more seamlessly integrate together seems like a more 'Apple' thing to do.

Maybe the black version just wasn't ready yet?

What do you think?