FlyBe have made an initial commitment to base several a/c there from 2006 on completion of the terminal.
I hope FlyBe are not looking for 20-minute turnrounds landing to take-off at Southend: the airspace can't handle Luton's, London City's & Stansted's present-day traffic without causing snarl-ups and take-off delays, and there's unlikely to be any improvement by 2006...
FlyBe operating out of Southend will just make matters even worse!