As of 22:30 Sunday evening, the latest indications are that the debris that broke loose from one of the fuel tanks during launch "may have caused more damage than initially assumed." However, the talking heads cheerfully went on to report that there was no way for the crew to have repaired the damage in space, so if that was the cause they were toast from the moment the debris hit the wing.
I am disgusted at NASA. What is it with these people? They've had tiles break off before, and they know how important they are. It seems to me that sending a shuttle up without some kind of tile repair kit is like wheeling without a spare tire -- with the consequences multiplied by a factor of infinity!
I hope the lead mission controller who decided the damage was inconsequential is proud of himself right now.