Specs are pretty limited but the card has 1GB of GDDR5 VRAM (256-bit interface) per GF104 and Expreview mentions the possibility of a 4GB model. The GPUs are connected internally through an NF200 bridge chip, so it should run fine on non-SLI motherboards. There's also an external SLI connector, meaning quad-SLI should be possible.
The card is powered via two 8-pin PCIe connectors and there's an extra chunk of PCB dedicated to the MOSFETS, solid capacitors and VRMs. Connectivity includes four DVI outputs and one mini-HDMI port. There's no word on pricing, but with Nvidia's recent cuts, we'd expect the dual-GPU GTX 460 to be reasonably priced if it makes it to market.