It would be the end of Jet2 if they moved into STN. Say they put a couple of 737's there we all know exactly what Ryanair will do .... put 3 or 4 737s up at LBA. It would not be worth the hassle. Jet2 should not expand into new airports at this time, they need to focus on their proven profit making routes not new routes that will be thin to start with and will be operating at a loss for a substantial period of time to cover start up costs.
Lets just wait and see what summer 08 brings for Jet2.