The big news circulating in the forums is that apparently the entire specs of the upcoming AMD Radeon 4800-series GPUs has leaked out.  The GPU is internally known as the RV770 and the end version will sport 480 stream processors and consist of 800+ million transistors while maintaining the 256-bit memory bus and will be built on the same 55nm process technology that the RV670s used.
Let’s have a look at the general specifications of the Radeon 4800 series, which is based on the RV770 graphics processor. The new GPU has 480 stream processors or shader units (96+384), 32 Texture units (up from 16), 16 ROP (same as 2900/3800), a 256-bit memory controller and native GDDR3/4/5 support (expect GDDR3 and GDDR5 memory versions of RV770 cards).

The transistor count has jumped from 666 million in the RV670 to more than 800 million transistors in the RV770.

New for the 4800 series is AMD’s decision to split the clock of the GPU and shaders, following a move that Nvidia made with the GeForce 8800: Back then, the shaders were clocked at 1.35 GHz, while the rest of the chip ticked at 575 MHz.