It isn't that far fetched. If a way could be designed to enable the TPGs to add their multiple opinions to a single generic slab, all of the TPGs could make more money through multiple certifications of the same coin. Then you might have something like a PCGS65/NGC64/ANACS64 -- then let the market sort out what it is worth. But I doubt they are that smart or cooperative.
I'd like to see an authentification service. They could charge a more reasonable price than the TPG's to just verify the coin is an authentic, unaltered coin. I mean lets face it, we don't all collect $500 coins. This would give us a chance to make sure even common date Morgans are the real thing.
There used to be such a service. After the ANA sold ANACS they started up ANAAB that only did authentications. But the service was so under used that it had problems holding staff which resulted in longer and longer turn around times. They finally gave up and the service closed down in November of I believe 2005.