There have been numerous rumours over the last few years about a full time EXT base for FCA, the latest that i'm aware of is that a 321 to be based from next summer 08, but as I said this is just rumour.
The problem for EXT as has been said before is that they've made it very hard for any other operator to recieve a good service down there, they tend to give a lot of priority to BE, also things like de-icing is done by BE so any other operator will be put to back of que, there is also very limited ramp and terminal space.
FCA certainly have a healthy intrest in EXT and the airport management does its best to maintain that relationship well.
What may go against an EXT base is the fact that BRS just up the road is a very strong base for them, 3rd busiest after LGW/MAN.
But then again it's no difference to BHX/EMA so who knows.
