Maybe Germanwings will consider to move there? As I understand, they have a lot of business from Ford originating in CGN now that Ford no longer operates its company shuttle between CGN and SEN, so a move would probably please one of Germanwings biggest customers.
Not before long there will be only a handful of airlines offering year-round scheduled services from STN (Ryanair, Easyjet, Aurigny, bmibay, Turkish, Windjet - did I miss anyone?).