Anything to do with bitcoins based in the US, all of the exchanges, etc. Even the overseas stuff with get cracked down on, especially any of the big players. Maybe not right away, but it'll happen.
Any business dealing with bitcoins or maybe even those accepting bitcoins as payments will become potential targets. Have their bank accounts subject to being frozen and whatnot. Criminal charges are possible too.
Banks and governments don't like competition. They are slow to act, but when they do wake up and decide to do something, it's usually not pretty. Bitcoin is making the same mistakes that e-gold made back in the day. History repeating itself.