Back in the day when we spent countless hours out there, it was our understanding that there was 10 additional acres on the east side of the park (just east of the football field) that was county-owned for future expansion. While I haven't looked at any plans, in my mind I assumed that is where the playground would go.
That being said, though, parking has ALWAYS been an issue. It was adequate 5 to 10 years ago, for activities one at a time, though you had to be careful not to back into another vehicle or run over a kid. Get two or more activities, especially with visiting teams, going on and there could be issues.
I'm all for state forest, but kids are our future, and youth sports do make a difference.