There is a big chance that Intel doesn't want to allow Nvidia to run SLI, as it doesn't want to make a big thing about SLI on its own Conroe machines.
Intel is in the bed with ATI and signed a cross-licensing agreement quite some time ago, the upshot of which is that it officially supports ATI's Crossfire on Intel 975/965 boards. We hear that Intel doesn't want to let Nvidia's SLI to run on its boards, at least not officially.
There will no-doubt be a leaked driver that will allow such a scenario, but even if the high-end tweakers society might be happy about it, none of the system integrators or OEMs will make such a machine as the driver would never be official and WHQL.
It is a funny old game but we will try to get to the bottom of it. µ
See Also
Geeks get Quad SLI to work on a 965 Conroe board
Nforce 590SLI to use old C19 chip for Conroe
ATI offers Conroe Crossfire incentive