Just as I was posting this, the Endeavour landing opportunity at 7:05 PM (2305 UTC) was waved off due to poor weather.
This leaves a second opportunity at 8:39 PM Eastern (0039 Thursday UTC). The shuttle's backup sites for landing, Edwards Air Force Base, Calif., and White Sands Space Harbor, N.M., were not activated Wednesday.
Weather seems to be improving, but if this second one waves off, they'll try again Thursday.
Two hours after landing, NASA officials will hold a media briefing to discuss the mission.