From Anandtech:

"MSI confirmed with us that they are canceling their plans for an "SLI"-like motherboard based on the nForce4 Ultra chipset after pressure from nVidia to drop the project. The MSI "semi-SLI" Ultra has been mentioned a few times in the past, but apparently, the newest NVIDIA drivers prevent this SLI hack from working. EPoX and DFI are both introducing boards using a very similar principle to MSI's DBS solution, but they both also face the threat of NVIDIA pulling the plug with next generation drivers."

Not suprising There goes my plans of buying a cheap Ultra board and running "fake SLI" sometime in the future.