As far as I'm aware most bitcoin exchanges don't adopt fiat currency as it requires them to be licenced with the money markets.
The same goes for the forex markets which exist such as IG Index or Capital Markets. The situation which would allow them to trade bitcoins for money is not suitable as it's not recognised as legal tender and organisations such as the IMF would not accept trading on licenced exchanges.
It's rather safe to assume for major players in the money markets would be unable to adopt bitcoins due to the red tape involved.
A small quote from the best exchange I am on
Our business and services are buying, selling and trading virtual goods and commodities. We are not currently regulated as a financial institution."