Frankly, I'd be happy if bitcoin facilitated these "criminal" transactions to a much greater degree. I'm absolutely no fan of Iran or Cuba or any of the other sanctioned countries, but I think the idea that economic sanctions do more harm than good.
If BTC (or some analogous currency) does become a standard value store on the international market, I'll be interested to see if governments continue pursuing the impossible goal of imposing economic sanctions like this or if they change tactics. My guess is they'll continue pursuing the impossible goal.