The companies running exchanges have already been shut out and are currently doing just fine without bank accounts. The main thing a bank offers you is security

The companies running exchanges have already been shut out and are currently doing just fine without bank accounts. The main thing a bank offers you is security of your assets; they have vaults for their dollar and BitCoin reserves. The other thing about financial institutions is that if there is an investment opportunity that gives them the possibility of making a ton of money they will take it. As soon as they see that they can make money off of BitCoin they will welcome the exchanges with open arms. I would have agreed that it wouldn't survive the mainstream if there was a danger of a serious attempt by the United States, the EU or China to ban its use. But it appears that government agencies are smiling on BitCoin, and both the United States government and the Chinese government appear to be embracing it. I suspect because if it becomes the world reserve currency it neutralizes the advantage that both parties have in manipulating financial markets (China by not allowing its currency to float and the US by, well, bailing out its financial system every time it leverages itself to the hilt and crashes which sends ripples through the world banking system.) The US and China want to neutralize the others' ability to manipulate their economies through monetary policy, and BitCoin gives them that opportunity.