NASA has waived off any further space shuttle launch attempts for the December launch window. NASA’s shuttle home page has a quick note about that:
The launch of space shuttle Atlantis has been rescheduled for no earlier than Jan. 2, 2008. The postponement will give engineers time to evaluate false readings from the engine cutoff sensor system that measures liquid hydrogen in the external tank.
As far as I know, a January, 2nd launch will be around 5:45am ET.
It is actually no surprise to me, given the new sensor problems. There is not much more news available as of now, I will keep you posted as I get updates.