I don't know how they calculate those scores, but here's my take:
Screen: D800 just a bit worse than the 5D2, nothing fancy.
Print: pretty much same as the D3S (on the print score you can see the noise-reduction kick in above iso6k on both nikons).
Print: D800 just keeps going up past 14 bits at iso50, beats the 5D2 and D3S (but D3S wins above iso1600). D800 a half a bit above D3X the whole way.
Screen: D800 and 5D2 are the same above iso400, but below it just keeps going in a straight line, 5D2 plateus out. D3S still beats both above iso400. D800 about 1/4 stop above D3X the whole way.
Print: D3S and D800 almost the same, D3X just a smidge below, 5D2 a smidge below that.
Screen: D3S a stop above the D3X, D800, 5D2 all the same.
Print: D800 for the low iso, D3s for the high, otherwise neck and neck, D3X just a bit less. Nikons are a bit or two above 5D2.
Screen: D800 just just above 5D2, both tied with D3X (you can really see nikon's boost above iso6400). D3s beats them both easily.
So what's so good about this sensor? Personally, I don't see much groundbreaking about it besides the 36MP. Noise levels are near enough to the same as the previous generation. 5D3 should beat it easily and maybe get into D3S-beating territory.
DR is a half-step above D3X, at least it doesn't 'plateau' like the 5D2 and D3S. I hope the 5D3 doesn't plateau at low iso like the 5D2.
Tonal range, just a smidge improved on D3X again.
Ditto colours, only a minor incremental improvement on D3X.
So it's good for landscapes at low-iso, and no worse than the 5D2 at high-iso. If the 5D3 really does improve by as much as canon's marketing tells us, then it should easily beat the D800 for everything other than megapixels...