Location Based Services: What’s Your Take?

It’s no secret that at this years SXSW f8 conference Facebook will be announcing and probably launching its location service. This will potentially bring 400+ million Facebook users into the location based market. Does Facebook entering into this market legitimize what Foursquare and Gowalla have already been doing? Should Foursquare and Gowalla be worried about Facebook’s entrance into their market? Are you looking at advertising and marketing opportunities for your business or brand in the location bases services market?