Why cloud cuckoo land? Is there something wrong with the idea or do you simply think there are too many vested interests for it to happen. I would agree on the second but I fail to see anything wrong with the concept.
Lets face it when we had the gold standard instead of so called "floating" currency values the world worked perfectly well. It may not have been a fixed universal currency but by and large you knew where you stood with exchange rates. To a degree gold is still a standard it is just that transporting it around the world is a bit of a problem and many regimes restrict the amount of currency or gold that you can carry across borders.