From wikipedia: Remittances totaled US$414 billion in 2009.

You know how much Western Union charges? At what rates?

There are whole countries living of providing the service Bitcoin provides. People actually fly to this places to store their money.

From wikipedia:  Tax havens have 1.2% of the world's population and hold 26% of the world's wealth, including 31% of the net profits of United States multinationals.

Someone, somwhere, will allow you to exchange Bitcoins. Be it in Japan, Switzerland, Isle of man, or Sealand. It will boom and crash, but it's too convenient to completely fail. It just must fly under the radar long enough.