[UPDATE (Sep. 24): The detections are real! I have the details in a followup post.]
Three separate spacecraft have apparently found the presence of water on the Moon... kinda. And by kinda, I mean it's in very small amounts all over the surface, and that a lot of it is not comprised of a complete molecule of water, but is instead found as a hydroxyl molecule (OH-), a water molecule with a hydrogen atom stripped off.
Let me be clear: the amounts we're talking about here are pretty small. However, scientists didn't really expect to see any, so it's a surprise. Also, the amounts fluctuate in rhythm with the lunar day, so it looks like the Sun has something to do with this - scientists speculate the hydrogen in the solar wind may be blasting the surface of the Moon, freeing oxygen from the rocks there and binding with it to form OH- and water.
Also, this is not the same as vast deposits of water that we're still hoping to find locked up in permanently shadowed deep craters. This is spread out all over the Moon's surface. I imagine it adds up to quite a lot of water, but it would be so thin that mining it from the surface would prove difficult.
You can read about this more at Universe Today. This news was embargoed and supposed to be released on Thursday, but for some reason the news veil was lifted early. I have not been able to find links to the scientific papers about this, nor any original sources -- none of the blog or news entries I've seen about this link to the sources, and there is no word of this on the NASA, Cassini, Deep Impact, or Chandrayaan-1 websites (those last three are the spacecraft involved with the discovery).
So for now I am taking this news with a modicum of (dissolved) salt, until I hear the press conference tomorrow and get the info directly form the sources. But I'll report on it then!