By the way,i just saw this posted by the same user of the video.SLI with udk.
Can anyone with sli confirm?
Some time ago i did saw on the forums that for crossfire,you can rename the udks game exe to alice madness returns and that way it shoud pick up from the profile drivers the crossfire set up of that UE3 game and apply it to your udk game.No idea if it works.