NVIDIA has allowed SLI on X58 motherboards. If we do not consider the Intel Skulltrail platform and the HP Blackbird 002, it was the first time SLI was enabled on a non-NVIDIA motherboard. However, it is now possible to enable it on a few other chipsets.
Most people agree that NVIDIA chipsets for Intel socket 775 processors are not worth much when it comes down to overclocking, so this could allow both insane FSBs seen on Intel chipsets and SLI technology at the same time.
So let's go straight to the experiment. Apparently, Firewings [CCG], the author of the little software that would allow this hack, was able to get SLI to work on his ASUS Maximus Formula, when running in the Directory Services Restore Mode. However, Firewings [CCG] is confident that he will soon get it to work under normal mode. Moreover, it seems he got it working using a GTX 260 and a... 8600GT! That would mean he has achieved two hacks at once.
Expreview has run their own tests using the second version of the ASUS motherboard and a pair of GTX 260, and it was a success.
Who knows, maybe later it will be made to work on the P35 chipset, and on AMD motherboards!