Hi Ray,
The majority of RAF A330's MAN has seen is either for paining or initial reg transfer maintenance (Monarch bring the aircraft into service under a civilian G- reg and then transfer it to the ZZ military register for the RAF), so Im not sure if they will be regular visitors or if the RAF will now keep the general work in house.
As for Air Asia X, I personally saw a delegation of D7 managers at a hotel in Manchester, so, Im unsure whether the work will be frequent and they have paid for long term usage of MAN, or if its a one off, or indeed if the work will be transferred to BHX. (I personally think it was a large delegation if just a 1 off visit, which is why I thought maybe Air Asia were starting MAN flights)
As it stands, obviously MAN will require work to complete as well as BHX and LTN, so I think its safe to say BHX will not see all of the future work, and MAN will likely have 1 set of contracts, BHX another and LTN another too (At the moment LTN MAEL sees the 'older' aircraft like the B757's and A300's (as well as those examples from FedEx), and MAN sees the new 'fly by wire' stuff like the A330's and B767's.
Im unsure at this stage just exactly which role BHX will take, but with 2 bays its going to be looking after something!