Quote from BENG:
The effect could be devastating to US dollars. OPEC might observe Iran's situation, and if they like it and switch to Euro as well, dollar will no longer be associated with a real asset. It's a bad bad thing.
I'm going to switch my trading ccount base currency to Euro, been thinking about it for a long time, this is the trigger. Better be safe than sorry, US dollars are already 35% overvalue. To say that it would collapse, it might be too harsh, but it should bleed to death slowly JMHO.