I understand that their future was subject to a temporary reprieve rather than made secure. You can view a potted history of the planning battle at
http://www.airfields.org.uk/rochester.htm
The public inquiry into the local plan as it relates to the airfield is due in April, and the current operators lease is until 2004.
In the meantime the local authorities seem intent on pursuing their ambition to close and redevelop the airfield.
a4a