The main ascent components seemed to work, although no telemetry results have been revealed yet. As the dummy upper stage/spacecraft/abort system separated, it tumbled violently instead of coasting along the flight path, as if unguided. As it appeared certain to swing around and impact the coasting booster, they froze the NASA-TV feed. According to NASASpaceflight.com, only two parachutes on the booster deployed. There was no live coverage of the descending booster, and controllers appeared to have lost all live communication with the flight systems.
[nm about the ascent plume business—I suspect it was a view as the nozzle gimballed away, then they switched flight cameras.]
Mostly successful in that it didn’t hit the tower and fly sideways into Atlantis on the other pad, or shake itself to bits on ascent. But since it was essentially a Shuttle SRB in a manned spacecraft costume, the relevance to future development will be a matter of marketing rather than actual engineering.