As speculation regarding the 9800 GX2 finally settles down, various pictures, specifications and benchmarks of Nvidia's 9800 GTX have surfaced. The board's core, shader and memory speeds will supposedly be 673MHz, 1683MHz and 1100MHz respectively. The only thing that separates the board from current G92 offerings (apart from slightly higher clocks) is support for three-way SLI, though the provided pictures don't support this, as only one SLI connector is visible (two are required).
The memory interface is 256-bit with 512MB of 136-pin BGA GDDR3 memory onboard. It comes with two DVI-I and one HDTV-out. There are two SLI connectors and two 6-pin PCIe power connector. The card employs the CoolerMaster TM67 cooler where the fan is rated at 0.34A, 4.08W, 2900rpm, 34dBA. The total board power is 168W. 
For clarification, a GPU-Z screenshot has been published which supports all the above info. Additional information points to a length of 10.5 inches, and a power consumption of 168W. One 3DMark 06 benchmark has surfaced, and 14,014 points is all the board can offer. As always, allow for some leeway due to buggy drivers.