So perk, here is something of interest. They are working on a thunderbolt version supposedly, but it is currently ExpressCard for laptops. Oddly, express card is only 1xPCI, which is 2.5gb/s which is WAY less than a high end gfx card would need, since most are 8x. But I wonder if they are 8x for multichannel, not bandwidth.
http://4sp.in/70Oalso, you can DIY it.
http://4sp.in/70Pthis would be awesome in thunderbolt and solve my issue.