Previously the Apollo moon missions gave the impression that the Moon's surface was completely dry. However, the astronauts only explored non-polar regions that receive plenty of sunlight. Around the poles the terrain is much more hilly and there are plenty of spots that are covered in permanent shade. Even where the Moon missions occurred there is evidence of some water ice underneath the surface.
While life as we know it cannot survive on the Moon the discovery of water is still important. Since water is so heavy and therefore hard to transport it was seen as a huge blocking point in lunar colonization. Now we have a vast amount of water available not only for human consumption but also things like lunar nuclear plants.
The new main problem is that water on the Moon is hardly what one can consider a renewable resource. The discovery; however, buys us time to figure out water transport/production issues while giving us a head start on possible exploration and other lunar economic activity.
All we have to do now is remember the economical benefits of lunar exploration. The Chinese, Indians, and other already have. Now if only physical geographers would get into the act and help with mapping the water spots. Sadly, I fear only geologists will apply themselves to this important mission.