Also if property values improve too much in Dolores Park or any of the areas around it no one will be able to afford to live there.
This is a good and funny question! Maybe the South end of the park will be more focused on those soccer moms and their children and the North side will be full of 'hipsters'. Either way, people will have to make room for both and find a way to get along.
There is no doubt that the new playground brings in more of a focus on families nearby and can only help the values in the area. I certainly couldn't imagine that something that nice would bring prices down but stranger things have happened in the world.