Recent findings indicate that water plays a "crucial" role in star and planetary system formation.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=46983
Our own solar system, from the Earth orbit outwards, has a considerable amount of water-bearing objects, our own planet and moon, Mars, asteroid belt objects like the dwarf planet Ceres, moons and rings of the gas giants, and probably all the gas giants themselves, Kuiper belt objects including dwarf planets Pluto and Charon, and the Oort Cloud, and all the cometary objects that entertain earthly observers, from known period and sporadic comets and their dust trails that result in meteor showers, and the mostly unobserved "small comets" that could be depositing an estimated 300 million tons of water (as well as some carbon-containing compounds) into the Earth's atmosphere annually, in addition to the few tens of thousand tons of dry meteoric dust that falls to Earth on regular annual and multidecadal patterns. None of these infalls play a part in climate models, incidentally.
http://smallcomets.physics.uiowa.edu/
http://www.talkorigins.org/faqs/moon-dust.html