I think it is highly unlikely that there will be a long stand-down this time as followed 51-L.
For one thing, NASA can’t do it. Progress and Soyuz flights can be used to periodically reboost the station, but it would be (as I understand it) extremely impractical to use Soyuz for crew rotation on such a short notice as this (due to production rates and the number of flights that would be required). The ISS crew has available a Soyuz for their return, so they aren’t trapped up there like the cosmonauts on Mir when the USSR disintegrated. Soyuz could be used to ferry up a replacement crew in the manner of the Apollos supporting Skylab, but there is no way that NASA can use other vehicles for delivering science payloads or station elements. This would cut into the station assembly schedule, driving the costs (even further) through the roof. No, NASA can’t afford another 2 year, 8 month stand-down.
For another thing, this isn’t such a shock as was Challenger. Back then, Shuttle flights were touted as routine and safe…safe enough for a civilian educator to fly, whose presence compounded the shock of the disaster even further by focusing more public attention on that flight than any other perhaps since STS-1. We’ve been told ever since that spaceflight has inherent dangers, that it shouldn’t be regarded as safe and routine in the way it had been before 51-L. It’s a shock, but it’s one that the American people are likely to take in stride this time.
We will be flying again this year. This won’t by any stretch of the imagination end the space program.
But what happens now with other programs? Will this accident result in another Shuttle Orbiter being built from the tooling and structural spares now in storage (as happened with Endeavor)? Or will it provide the push required to actually make someting from OSP? What will happen to Prometheus, now that the anti-nuclear watermelons have a bold, front-page event to point to to “prove” their case that spaceflight is too dangerous for nuclear materials? Will the space program be slowed as a result of this?