a whole bunch of pictures of the upcoming GeForce 9800 GTX in the nude and it looks very different from the GeForce 8800 GTX that they've put next to it on one of the pictures. The card is about as long as the old 8800 GTX, but as it's using a 256-bit memory interface, it has a very different board layout.
What is striking in the pictures is the power regulation part of the card; it has a huge amount of solid capacitors, more than we've ever seen on a graphics card before, and if the information is indeed correct, it's using a four phase PWM for the GPU and a two phase design for the memory.
The card does, of course, support 3-Way SLI, as it has a pair of connectors toward the front of the PCB. The reference card has a pair of dual link DVI ports and a TV-out connector, but there's also some wierd connection between the PCB and the rear I/O shield. This might be some kind of support brace, but it looks very strange and we've never seen anything like it on past Nvidia cards.
You can check out the pictures here