If one thing is certain about the computer market, its that things are always in a state of flux. The proposed merger between ATI and AMD means that we'll likely see more ATI motherboard chipsets on the market. NVIDIA has committed to support the AMD platform and AMD has committed to an open platform for their CPUs and chipsets. How it will play out will be interesting.
The EVGA 123-K8-NF47-AX is an excellent example of the nForce4 SLI x16 platform. With the recent launch of the Socket AM2 platform, the Socket 939 CPUs will likely disappear over time. For those wanting to upgrade their nForce3 motherboards or wanting to move to SLI without changing their CPU and memory, the nForce4 SLI x16 platform is a good alternative to the AM2, as moving to the new platform requires a new CPU, and new memory. The EVGA board can be had for $143 on Newegg at this moment. EVGA offers a Lifetime warranty on all of their video cards and motherboards with an AR, AX, BR, BX, DR, DX, FR, FX, SG, SL, and S2 prefixes.