SLI in MacPro?

When acquiring a MacPro, Apple advertises that you can install up to 4 graphic cards, such as the nVidia Geforce 7300. This card can be associated with another identical one to be used as a SLI system developed by nVidia (running WinXP); 3D performances are then strongly improved.
One of the question was: is it possible to built an SLI system in the MacPro?
So far, SLI requires the nVidia chipset nForce4; even though some rumours are circulating concerning the opening of SLI to other chipset manufacturers, such as Intel.
A reader from Apple's Forum reports to have modified a nVidia driver and successfully setup via WinXP a SLI system in his MacPro. Results of the provided 3DMark2006 benchmarks shows a doubling of video performance.
Now, will we be able to make a SLI system while running Mac OSX?
PS: We will provide a in depth analysis tomorrow regarding this topic.