It would also have to maintain the >50% hashing power for more than 120 blocks. And even then it's not guaranteed as smaller pools could get lucky and solve more blocks than the larger rouge miner.
Just another reason to adopt Namecoin as an alternate DNS provider. Lots of work still needs to be done though for it to be easy enough to use by the average user.
It looks like they have 7 cards in there.
If all the GPU's in that system where pegged at 100% for 30 minutes that system would overheat.
There isn't enough space between the cards for free air flow.
7 x 5970's would give you just under 35 Teraflops instead of 12.