I haven't heard anything about bmibaby wanting to move over to T2, I would think that the airport would be keen to keep low-cost airlines in T1 in order to try to maintain some of the costs lost by landing charges back through retail fees, I believe this is the way airport operators work. flybe often touts the benefits of regional airports (small walks from car park to aircraft, small security queues, less shopping mall more transport interchange) which T2 seems to fit perfectly. Also the average size of their aircraft (78-seat Q400s and 118-seat EMB-195s) seem to fit T2 better than baby's 148-seat B737-300s.