I'm .. really not sure why you'd need 2Gb of memory on your garphics card at this timeframe, but PowerColor is developing such a product none the less. The card has 2GB of on-board (framebufffer) memory which is four times more than normal. The card will obviously be equipped with a 55nm, 800 Stream Processors-boasting RV770 GPU clocked at 665 MHz (625 MHz stock) and 2000 MHz-clocked memory, and CrossFireX support.
PowerColor working on 2GB Radeon HD 4850