I Believe with the eminent release of Steam and Nvidia's recent improvements this question is relevant. If Ubuntu (and overall Linux) is to be a viable alternative to Windows for gaming I believe SLI needs to be supported.
And so, this got me thinking. What would it take? Is it an Nvidia thing? Or would it have to be written into the kernel? And either way, how can we as users make this happen?
I personally would pay for a kickstarter campaign or fundraiser etc, to raise funds to help the progress along. I would love to see SLI working in linux, wouldn't you? Please share your thoughts and ideas.