It is MST. When you first boot the computer you get two images, side by side of the exact same thing as the Bios boots. Then when the windows logo shows up you also get a side by side of the same image. Once this disappears, the TV gives the "no signal" image, then immediately the Windows's image appears full screen. Going into the "set resolution" screen it appears as one screen. I also confirmed with a guy called Lars (he is the one in the Nvidia video above) and prior to getting the set he confirmed MST as well. Here is what he had to say when I sent him a message via Facebook.:
"Hi John, ah, now I understand. There should be no issues. Some older game engines have issues running at the higher res, but in common, everything just works. But as a general statement, 4K is new and there might be some bugs here and there. But since there's lots of focus on 4K, they should get fixed quickly.
You're right about SST. Problem is, there are no panel display controllers today who can handle DP60 Hz at 4K resolution. This is why all panel makers are using MST today to get to 4K@60Hz. It's expected that such controllers will be ready sometime next year for prototyping. So we think it will take until end 2014 or 2015 until we see SST solutions with 60Hz at 4K res. When the TV arrives, just make sure to have the 331.40 drivers running on the system".
You guys speak of MST as a negative. When viewing a 4K 60hz game, will I be able to see any kind of difference between MST and SST?