The only ways around this would be for the deposit taker to either receive authorization from the SEC (yeah right), or try to block American clients. Satoshi Dice started doing this with an IP checker (though it is not hard to get around it). I think this is sufficient to remain out of the regulator's crosshairs as it is enough to show that they are not actively seeking US-based clients.
It is very naive to believe that blocking US IPs will prevent from crackdown! Erik Voorhees already understand this and took proactive measures (i.e. sold SatoshiDICE while fools still believe IP blocking will save from govt attack and thus ready to pay $12M).
The only safe way is to move away from the U.S./its friendly countries IMHO. Most "grey" BTC service owners will do this in the future when pressure become too tough.