Good lord! this is the fastest memory I've ever seen! How much does this memory kit cost?

Apparently it was designed specifically for the ASUS Rampage IV Extreme X79 enthusiast motherboard.

How do they run it at those speeds without it becoming unstable or overheating?

They must have huge heatsinks which require tons of airflow to keep them cool.

http://xtreview.com/addcomment-id-21205-view-...6-MHz.html