The ASUS P5N32-SLI Deluxe is an excellent example of NVIDIA's nForce4 for Intel x16 SLI motherboards. The fact that I was able to install and run an X6800 Core 2 Extreme CPU on the board is a definite plus, as the new Intel CPUs are the fastest on the market today. If you want HDA and the new features of the nForce 590 series grab the 590 boards when they reach the market.
Feature-wise, you get full on SLI (2 x16 lanes) when two video cards installed, 6 SATA ports, Firewire 6 USB 2.0 ports and support for up to 16GB of DDR2 memory. Major features added on to nForce 590 for Intel include LinkBoost, DualNet, H.D.A and more. If I wanted to buy an SLI board today the ASUS P5N32-SLI Deluxe would be the top of the list. There are few negatives of the board including no High Definition Audio, and that NVIDIA has released the new 590 chipset. We'll have to wait and see how the proposed merger between ATI and AMD turns the market place for motherboards into. ATI provides a lot of motherboards for the Intel market and Intel has apparently pulled ATI's Front Side Bus license. The consequences of the merger may see a closer alignment between NVIDIA and Intel and a higher concentration of NVIDIA on Intel chipsets. With Windows Vista looming Intel may decide to use an NVIDIA integrated GPU if their GMA3000 doesn't cut it.