Considering the catchment area of Edinburgh compared to Aberdeen I think Edinburgh is far more likely.
By the way is anyone ever going to do a Stansted service again from ABZ. Surely someone could make a profit on it. Afterall people visiting London could use it (the easyJet Luton service seems to do good business) as well as those visiting East Anglia, Essex and East side of the M25 area etc. If it was promoted properly Aberdeen residents could be made aware of all the potential low-cost destinations from Stansted that they could connect to.