I assumed someone had made some sort of 'arb-bot' across the three, but it makes sense there was some sort of inter-exchange co-operation. maybe it was a dry run, but it is effectively a currency price control 'peg' and will fail if big money wants to bust it. Perhaps the idea is to prevent one exchange being singled out for a move, spreading the load - do the exchanges trust each other enough to agree...?
Whenever there's the will, there's an action... I know about urm...
11,020,102,425 USD
or 7,716,496,363 EUR
or 32,126,811,250 PLN
or 6,730,991,273 GBP
OR 12,122,975 BTC for them to agree on a common purpose.
You are leaving out greed and what is in game theory known as 'the prisoner's dilemma' - why would the Russian-based Btc-e trust Mark at Gox to not act in his own best interests in spite of any 'agreement' that is in all their best interests IF it holds?
Once the market gets volatile - it always will get to the point when 'each to their own' at some point. Self-interest in markets always prevails in the end.
All fractional banking-style banks cannot withstand a run, so if everyone acts rationally - and does not join a collective demand for their money back, all will be fine (in theory).
But runs on banks only pay the first in the queue, so everyone wants to be first. Exchange co-operation will be ok in smooth waters, but not in calamitous times - ask Mr. Soros?
I watch with interest - but it's a Darwinian and (relatively) unregulated market - so I think it's 'no prisoners' if it comes to crisis point.