According to this articleon Slashdot (and there are lots more in various places – I just like Slashdot), NASA plans to set off an explosion on the moon that will create a 6 mile high debris plume so that they can look for water in the debris.
On the serious side, if they find a significant source water it would be another major step toward starting a real lunar colony, because water is one of the most important resources (right up there with air and soil – well, with hydroponics, I guess soil is less important) that are currently absent on the moon.
But, really, it’s very hard to be serious when you’re talking about NASA blowing up the moon. I mean, have they thought about what could go wrong? Two moons, anyone? What would that do to our tides? Ah, the imagination can run wild. Thanks, NASA.