Probably a good move for Burger King to take some of the flying hippos space, place is always dead. It also thought looks as if the Beer House Pub is going to be extended into the current Burger King searing area from one of the drawings.
As far as new outlets are concerned the SSP mafia hold the contract for food and drink airside so any new openings would more than likely have to fit in with them rather than just say Subway deciding that they wanted to open a store up there.