I think it's inevitable for US based exchanges. They'll have to be regulated or move out of the us and not sell to us consumers.
This will definitely spook people. Keep your coins in your wallet and not on the exchange.
But some of the people in US try to use VPN or another. There is some exchange site based in US such as polo and coinbase. But i prefer to use the canadian exchange such as kraken or russian exchange.
It will be safe in my opinion.
The Canadian based exchanges will be next. Canada just follows US trends.
Call me conservative (i am dull martini after all) but I like my exchanges to be regulated. I wish there was some oversight of ico's so they wouldn't be so scammy...