Timber, having read your last post, I can't find much fault in what you say, frankly, and common sense would suggest your forecast will be correct regarding the new exchange.
However, I take a different tack and say that given the sheer volume of population that have a new toy to play with, the potential transactional volume could create a case of "tail wagging the dog". What if the comex market makers starts using shanghai as their reference point for laying off risk.
Nymex WTI used to be the bench mark for oil, until Brent came along. Now we have two markets that trade at fundamentally different prices, and the oil games that used to be played out on WTI eventually diminished. Sure, you can arb the two, but you can't seperate them. In other words, it isn't possible to make the market "yours", for you own gain anymore ( not that I think manipulation is a big issue anyway)
For what it's worth, giving CME a run for its money can only improve REAL price discovery.
One thing for sure, the conspiracy theorists won't be able to shriek manipulation any more