The US Dollar is losing value fast,
compared to other foreign currencies. This is due to many factors, the most recent of which is the credit crisis for housing mortgages in the USA. The long term ones is the debt for financing the invasion of Iraq, and the ongoing cost associated with that.
This is in stark contrast to the Canadian being worth only 62 cents in 2002, prior to the invasion of Iraq.
The oil rich countries in the Gulf have traditionally pegged their currencies to the US Dollar, for example is that 3.75 Saudi Riyals bought a dollar, and 3.68 Emirates Dirham bought a dollar.
However, Kuwait broke the peg of its dinar to the dollar last May to rein in soaring inflation. Saudi Arabia seems poised to follow, per this Telegraph article.
China's reaction will be cruical: they have threatened the nuclear option against the dollar last August.