My post before last turns out to have been premature. I should have known better. Even at the press conference just after impact the L-CROSS team seemed just a bit chipper and smooth, especially for guys whose heavily promo'd sky show had just gone bust. Their media leaks a few days ago were also just a bit coy. (And given the subject, 'leak' is a singularly appropriate term.)
The sky show may have been a bust for the Earth audience, but it was no bust for the instruments aboard the L-CROSS probe, or the Lunar Reconnaissance Orbiter passing 50 km overhead.
Cutting to the chase, team leader Anthony Colaprete reports that that they found water, and 'We didn't find just a little bit, we found a significant amount.' In fact, 100 kg of water vapor were detected in the plume. (The illo above is from the Sky & Telescope article, where it is explained.)
Colaprete wouldn't give an estimate for what fraction of the soil that might be, but on the face of it that is quite a lot, and apparently counts only vapor - ice either vaporized by the impact heat, or perhaps sublimating from crystals exposed to space, especially if kicked up high enough to be hit by sunlight.
A brew of other compounds was also detected, one of the inevitable candidates being ethanol. I hope that pans out, if only to see the estimates of how many fifths are locked up in the lunar regolith. However, the first potable moon juice will surely come from a still tucked away in the life support plant.