Discovery in possible heat tile trouble. Is the end of the US manned spaceflight at hand?

If there really is damage, the crew is safe if they just stuck on staying at the ISS and waiting for the Soyuz crafts to bring them down two at a time.

But even if there is not serious damage, the decision to launch the shuttle again will be hard to make as no one knows what will happen the next time and the whole heat tile arrangement has been proved very fragile to damage.