This thread seems to have degenerated into a discussion about a bridge chip, but I'll bite.
Seeing as I'm getting nearly 100% scaling with my GTX 460 SLI setup on a 16x/4x PCI-E 2.0 Crossfire motherboard, I don't really understand the need for a special chip. I'm sure it might help in some niche circumstances, but really it looks like a gimmick to try to encourage people to buy an nVidia motherboard.
Seeing as I'm getting nearly 100% scaling with my GTX 460 SLI setup on a 16x/4x PCI-E 2.0 Crossfire motherboard, I don't really understand the need for a special chip. I'm sure it might help in some niche circumstances, but really it looks like a gimmick to try to encourage people to buy an nVidia motherboard.