I am now following up on the launch scrub. Remeber, it is still unconfirmed, but the information looks pretty solid.
As it looks, the problem is indeed related to the ECO sensors that I just wrote about. Two of four seem to have failed, which can not easily be overruled.
The news is still not confirmed. If it is true, the shuttle is probably being detanked right now and the sensors are undergoing additional tests. Only after such tests it can be seen what needs to be done and how long the mission will be delayed. The delay is very unfortunate, because there is only a small launch window of 7 days to launch STS-122. If that fails, the next launch attempt can be in January 2008 at earliest. This would probably affect the whole shuttle schedule – and even Ares and Constellation – as they depend on STS-125 in summer, after which launch pad 39B will be handed over to constellation.