The first launch attempt of Space Shuttle Atlantis for STS-122 has been scrubbed due to two of four LH2 Engine Cutoff (ECO) sensors failing to respond during tanking. The ECO sensors detect when the Liquid Hydrogen tank is about to run dry and cause a main engine shutdown to protect the turbopumps from running dry which could lead to catastrophic engine failure.

LH2 and LOX fuels have now been detanked from the shuttle and there will be a launch countdown recycle with the next attempt at 20:43ZULU Saturday the 8th of December.

Update: Launch now postponed until January

I also discovered an alternative link for NASA TV via Yahoo! which appears to provide a better quality of video that the rather awful quality provided by the NASA TV landing page.