The new GPUs will have a 576 MHz core clock and a 1242 MHz shader clock. That's slightly slower than the GTX 280's 602 MHz core and 1296 MHz shader clocks, but the GTX 295 still wins in the GPU quantity column. The card will also have 1,792 MB of onboard GDDR3 memory clocked at 1,998 MHz.
The dual-slot cards will come with HDMI and two dual-link DVI outputs. The new chips are more power efficient, but two of them will still draw up to 289W according to Nvidia. Plan on picking up a 1kW+ if you plan on putting two of these together for Quad SLI.