Yeah. It's been in the news a bit lately.
Somewhere along the way cluster computers have gotten mixed in with supercomputers. VT essentially took 'off the shelf' Macs, stirred in high speed networking, a dash of custom software, and spread evenly across an ass load of floor space.
Still, the world's fastest supercomputer (not a knock off cluster) is over 3x faster and nearly two years old from launch time ... keeping in mind that the VT boys aren't even done yet.
I'm impressed. It's cool stuff. I just think clusters should be in their own catagory - not in with 'supercomputers'. Additionally, there is a good chance several other supercomputers will be added to the list this year. We'll see.