Until they figure out if it came from the shuttle, which is likely, they would be in fuel conservation mode. They have to maintain attitude and continuously reposition the shuttle if they were to be required to stay in orbit for a extended period of time.
Right now, they are beginning the survey of the bay. I suspect they will also do a EVA tomorrow and reinspect the entire shuttle.
If they find a serious problem, they would have to re-dock with the station at some point.
I hope it is just a protective blanket from the bay.
And if they had to do that, I think you can probably count on that Shuttle never coming home. Meaning that they've got the deorbit propellant available for the rendezvous.