MSNBC reported last week that the shuttle launch delayed by a fuel sonsor glitch ahs been pushed back until at least January 24 if not further.
"Deputy shuttle program manager John Shannon said the mission to the international space station is off until at least Jan. 24. “Everything has to go exactly right for us to make the 24th,” he said."
If delayed further into early Febuary, a launch could be complicated by the planned launch of a Russian Progress cargo vehicle to the ISS. Current docking rules at the station prohibit a shuttle docking while another vehicle is linked to the station. The shuttle would likely have to launch before January 26 for both mission to proceed without conflict. The issue with Atlantishas already impacted the scheduled Feb 14th launch for the next mission being flown by Endeavor, which was to have delivered a Japanese built lab module to the ISS. NASA procedures mandate a five week period between shuttle missions.