Uh, nope
Not gonna happen. Not now, anyway. This would be a non-linear modification of the other screen resolutions, which would require a completely new method of making your apps. You could make a case that they already did this with the iPhone 5, but this required a much less drastic conversion, and one could always just letterbox it.
I, for one, would not mind seeing a 12.9" screen with the same resolution as the 9.7". Yes, it would display the same information, but user elements would be much more usable for things like art and medical. I'll bet they're using the Retina resolutions from the 9.7" on the 12.9". If they're testing it at all...