The news wasn’t all good after the shuttle launch this morning–a piece of insulating foam fell off Discovery during lift-off:
NASA plans to do more tests to check if Discovery is safe to fly back as planned on Aug. 7. The foam piece is estimated to be 60 to 83 centimetres long, 25 to 36 centimetres wide and less than 10 centimetres thick–smaller than the 0.7-kilogram piece that hit Columbia’s wing during its lift-off.
If something is seriously wrong with the Discrovery, the astronauts can camp out in the International Space Station and enjoy some powdered borscht until a rescue.
DarrenBarefoot.com 
Your post is a bit confusing: at first I thought a piece of heat shielding had fallen off the shuttle itself. It turns out that it was (as with Columbia) a chunk of insulating foam from the external fuel tank–but this time it didn’t hit the shuttle itself, so there is no reason to think there would be any problem on re-entry.
The grounding of the fleet still makes sense, since flying debris could very well pose a danger to the _next_ shuttle flight. But there need be no addition borsht for this shuttle crew, who will probably head home as scheduled.
Sorry for the confusion.