I think they will just remain the same... Asiamiles members can earn points from Air China and Dragonair already. Drangonair Elite members cannot earn points on CX flight yet (I think, correct me if wrong), then after the acquisition, I guess KA members can then earn points by taking CX flights. But I don't think the programs will merge together as one...

(When you fly 30000 miles, you get only silver in MPC, but when you have 30000 miles, you are already Gold in KA, simply becuase they serve shorter routes with little miles each flight... How could these structure merge together, you see..)