From what you could see, would it be a good O venue?
Some of PSF would be fine, but there's a lot of crappy ATV trails, some thick Mountain Laurel/Rhododendron areas and most of the forest seems to be a steep hillside. It would probably make a really good area for a 24-hour rogaine. :-)
I have run trails many times at PSF and I don't remember ever thinking "Hey, this area should be mapped." I agree with Fred's assessment, although they've significantly restricted where ATVs can (legally) go, so that aspect is improving. It would be OK for local events, but the area isn't really "local" for many of the regular orienteering crowd. The area is pretty good for trail running, especially on the network of mountain bike trails which have been developed (through the efforts of local mtn bikers working with the park people, so they are park-sanctioned).