Really not the first time.
Some news reports said this was the first time water was directly detected on the surface.
Actually Viking did that 30 years ago with the GCMS mass spectrometer. Like the Phoenix TEGA, the Viking GCMS had a sample "full" indicator. However, unlike Phoenix they never got a "full" indication for any of the samples collected.
Since the Viking instrument failed to detect organics, the only way the Viking scientists know some sample was delivered was because they were able to detect the signature of H2O with the mass spectrometer.
Bob Clark