My first thought as well.
Bitcoin is often said to have many of the properties of gold, not least its scarcity.
But here is a clear example of how bitcoin trumps gold, people can move large amounts of bitcoin in a short amount of time with very little risk. Bitcoin users are already doing this.
http://blockexplorer.com/block/0000000000022043f9ea2c298f338...
Total BTC?: 416300.33
At todays bitcoin market value that is 4,605,201.67 USD.
Still some way off 12 billion I grant you, but astonishing considering gold has been used as currency for thousands of years and bitcoin is less than 3 years old.