The High Earth Orbit blog has an article discussing this question. Here is a snippet : "In my previous post about building a KML of the California green building directory I made a very off-hand comment about how a GoogleMap does not mean GIS. Andres has challenged my comment and provoked a very thoughtful discussion. My original comment was merely based on the original article of the Green Building site that seemed to imply that GoogleMaps alone meant a GIS. My feelings are that mapping tools have become ubiquitous and easy to use - not requiring advanced expertise to utilize for visualizing geospatial information." To read the full discussion, please head on over to the High Earth Orbit blog.
Read more of this story at Slashgeo.