Last week’s launch of “Facebook Places”, the new ‘geosocial’ feature of the gargantuan social media provider, makes me wonder what will happen to all the other geo-oriented competitors. As with other great ideas and big market opportunities, when the industry lead does something, there are usually repercussions. Already Hot Potato has fallen, absorbed like Microsoft swallowed Vermeer to get FrontPage. Who else will fall?

Venture favorite FourSquare likes the position they are in, and they even supported the Places press conference (likely partnering, along with Gowalla, on the API). But while the world can live with Ford and GM stomping around, the little guys like Saturn and DeLorean are likely to get pushed off the dance floor. 500 million users will tend to do that. Fringe players like Loopt and Mobcast may be in jeopardy. And while Google falls in the “big fish” category, their Latitude product has generated as much buzz as, well, their Buzz product.

I’m betting that Facebook is sure to dominate all others. Location services will prove to be best when they are both utilitarian and popular. Most others lack the well-established user base, and those that have gained popularity are used more like games than services (Gowalla as scavenger hunt, FourSquare for collecting mayoral points). The lure of 500 million Facebook users will draw the lion’s share of retail partnerships, and that will ultimately determine the true u$efulne$$ of $uch a $ervice.