HardOCP received MSI's Big Bang Fuzion motherboard with the Lucid Hydra multi-GPU technology. The site published some photos of the motherboard, a review will probably follow within a couple of days.
"The HYDRA engine scales performance of multi-GPU configuration from any single GPU vendor and will scale relative to their individual performance (the GPUs do not need to be identical). The intertesting thing there is "from any single GPU vendor." Then it does go on to document some "X-Mode"/"Multi vendor" GPU configurations using both NVIDIA and AMD GPUs avaible in Windows 7 only. You have to use NVIDIA G90/G200 GPUs with AMD HD4XXX series of GPUs. No support beyond that currently, and quite frankly I am going to suggest you will not see much support beyond that. On the final brown colored page you will note "Game Qualified" games. Under X-Mode we see only 5 actual games tested to support Lucic Hydra usage models.