I keep saying the same I was saying months ago, I could be wrong but I have the feeling I'm not: Versus won't be multi because the main target (for Nomura at least) is getting a bit hit in Japan, so they can't be bothered to make a port that won't help to that objective, especially if it affects the actual development (god knows it´s slow enough already.)
This, of course, is just a personal impression with nothing to back it, just my personal bet. Other thing is that I don't think Microsoft is that interested in getting Versus as it was for getting a mainline FF.