This isn't really "open space" as defined by the EPA as it is private property and not open to the public.
It's listed currently on the township's website as proposed township park land, located in an open space conservation district, and is shown on the the comp plan as Rural/Agricultural/Preserved future land use. The story is never simple. And for a good read and lessons learned from potential development of a golf course viewed in many respects as 'open space', go to http://www.keepthecourse.org/
I'd keep an eye on what Willistown Conservation Trust has to $ay on the matter. They've got some very deep pockets when it comes to protecting open space in that township.