Can't see it happening. Rudi said it best above. A combined ff program could not possibly offer all of the "pluses" of all of the individual ff programs. People would be upset about any cuts - so it's better to have many different programs that people can pick and choose between. (Something that Rudi has down to an art when he changes between LH Miles & More and UA Mileage Plus on a seemingly flight-by-flight basis. )