As a trader I'm happy to accept bitcoins, but no one has them so few people buy in this way.
I want it the other way round - ie a buyer can pay with their credit card, bank transfer etc and I receive payment in bitcoins (which I can easily convert to cash whenever I like).
This makes international trade much easier as the buyer does not need to be aware that transfer of value occurred in bitcoins.
There could be an open source payment checkout system that links to to the exchange of your choice in your own country, you press pay and the money is immediately converted to bitcoins in the local exchange and sent to the seller anywhere in the world. If the seller's exchange is connected to this system it could automatically convert the bitcoins to cash in the local currency (if the seller prefers cash).
All the exchanges around the world could function like a distributed paypal without having to open branches in every country.
No single entity needs to open it's own branch in every country - each exchange would be responsible for dealing with local legislation.
I like that idea, but the best solution is to pay in bitcoin everywhere, and get paid in bitcoin. then you never have to exchange in and out of USD.