It would be costly to build housing on Coventry airport. The land isn't that great, theres land to the north of the airfield which used to be an old dumping ground and your not even meant to do earthworks on it apparntly.
I think the key to Coventry's sucess will probably to be have as many fingers in as many different pies as possible. The airport would have made money had TUI continued to increase their passenger growth, however it seems to me that like alot of airlines they started off big (with understandably a loss in the first year due to the required infastructure to support them) but then when they had potential to make money the number of aircraft began to drop, instead of having 8 stands busy all day your left with 2 aircraft with 1 flight each a day but you've still got all the staff on you had for all stands busy. Its a no brainer. You can understand though if they want to expand their operation and move aircraft to other airports.
I should think the airport will carry on doing what it was doing. Buisness aviation, Cargo and GA/Flight Training. With alot of infastructure development (reading the ADP section it seems thats what they do). Most likely i think they will want to attract maintenance though. Perhaps a model similar to cambridge.