Well, every new invention has promised to make troops on the field obsolete - tanks, airplanes, machine guns - you name it. Hasn't happened yet. I do think that remotely controlled airplanes will replace piloted ones. An airplane can pull about 9G's turning pulling upwards, about 3G's going downwards. The limiting factor? The human being in the cockpit (all the blood runs into our out of the head - either way is bad). Take the human out of the equation and airplanes are capable of far more radical maneuvers. The only thing that would change that, IMHO, is if someone figures out a way to jam signals. Suppose you are flying half way around the world for a strike. If the airplane is flown remotely, pilots can trade-off, go home and have dinner with the family, etc.
But for land combat (and you can't do everything from the air), we'll need boots on the ground for the foreseeable future.