You're misunderstanding the relevance here. Water the molecule is common throughout the solar system, typically as ice. It makes up a significant fraction of the mass of many of the moons of outer planets. It's a common component of comets and other minor planetary bodies. Titan, for example, is about half water ice, but it is so cold there that it is effectively a rock.
What we've been learning is that there is water ice in some places we didn't necessarily expect it before (such as in the form of permafrost underlying much of the Martian surface) and most importantly that liquid water is not as uncommon as we once thought. Liquid water is what's most interesting from the point of view of looking for environments that can support life forms. Previously we thought that the presence of liquid water required not only the presence of water as a material but also overall planetary temperatures in a temperate range, the so called "habitable zone". Which, as it turns out, is a fairly narrow zone. But we've learned that there seem to be numerous circumstances that allow the existence of substantial quantities of liquid water in conditions that otherwise would not support it. Europa, for example, has frigid surface temperatures (150 to 200 degrees C below freezing) but it has a sub-surface ocean due to tidal interactions with its neighbors. That sort of thing seems to be much more common than we knew previously.
