From Space Flight Now:
"Until we're ready, we won't go fly again," said shuttle program manager Bill Parsons. "I don't know when that might be, I'll state that up front. We're just in the beginning of this process of understanding. This is a test flight. This is a flight we had to go off and try to get as much information as we could and see if the changes that we had made to the tank (in the wake of the Columbia disaster) were sufficient. Obviously, we have some more work to do."
Obviously, NASA is hosed. What happens if there's a need to rescue Discovery's crew? Do they just hang around the space station until the breakaway foam issue can be resolved? Given NASA's track record, they could wait for years.
Learn more about the disturbing mess by clicking here.