In the past couple of years, the following countries have stopped using the dollar as their reserve currency or have dropped their currency's peg against the dollar:

• China

• Japan

• Kuwait

• Syria

• Iran

• Libya

• Russia

• Malaysia

• Brazil

• Argentina

• Ecuador

• Switzerland

• Norway and some other Scandinavian countries

• Some Balkan countries

• Many East European currencies

The following countries are rumored to be considering dropping the dollar as their reserve currency or terminating their currency's peg against the dollar:

• The arab Gulf States

• Saudi Arabia

• South Korea

• Venezuela

• Sudan

As Assistant Secretary of the Treasury, and the "Father of Reagonomics", recently said: "The dollar’s reserve currency role is drawing to an end".

See also this article, this article, this report, this roundup, and this one.