That won't happen until 1BTC equals 1kg or at least one pound of Gold. One Oz is not that much money after all (2500$ is a month's wage in the Western Hemisphere).
1 bitcoin = 1 kg worth of gold will never to be real, It means the bitcoin must be worthed over ten thousand dollars.
OP, Bitcoin is not flipping the gold. My thought if the bitcoin is different with the gold itself. The value of the gold depends on the how many weight of the gold itself. And bitcoin is not.
I agree nice analytic and i will add that bitcoin is too different investment in gold they have both good price but one exist in online and one is a physical materials. I weight comparison we cant but in 1oz. of gold in equivalent of $ and 1 bitcoin will be the base .Bitcoins have a big price through a years past than gold.