NASA has known about the fresh snow, geological activity, orbit perturbations, tidal movement, elastic deformation, internal heating, and probable ice melt since 1982. The Voyager 2 image and analysis is here: http://photojournal.jpl.nasa.gov/catalog/PIA00347
Today's JPL discovery of "Potential Liquid Water" is nothing more than anti-discovery, welfare entitlement, posturing.
In the spring of 2008, scientists will get another chance to look at Enceladus when Cassini flies within 350 kilometers (approximately 220 miles), but much work remains after Cassini's four-year prime mission is over.