I would take as educated guess, and say defiantly will be a RAM upgrade..... BUT.... This extra RAM will be consumed in the handling of the 4 times more data that it will require to drive the Retina Display..
I am surprised that Apple didn't call this device the iPad2X, because the dual core main processor is the same as before (I suspect another iPad, maybe in the not to distant future that gives is quad core CPU as well as GPU?).
The new quad core graphics will all be consumed in controlling that display.... Apart from the idea of increased colour sauturation I am not sure about the need for such a HiRes Screen on such a relatively small device? Maybe it has to be seen to understood?