This is, indeed, good news. I ran across a study indicating that achieving such a low level post surgery was the strongest predictor of relapse-free survival. (Search on "Using PSA Intelligently to Manage Prostate Cancer".) Ultra-low PSA was a stronger predictor than any other variable, e.g. Gleason, margins, pre-op PSA, etc. I don't know if there have been subsequent studies to support or refute this, but it is worth a read.