I am in the US and when the law was passed I probably had more sites then you could imagine. All the sites that left the us market gave me time to withdraw. I was a depositor on almost every site I had which made a difference on some sites when I read the policy for withdrawing in the notices they sent out.
DoylesRoom room every time they have closed and then moved had transfered all of my funds.
Now their were a few sites that did close to all players such as Jetset poker, the DGS network (Jungle poker, OK USA. Wingowspoker, G2G which is now on merge and transfered most players funds over to the new network), DGN which had several sites close but the software developer has taken back over and is now the gold chip network (
Pokerworld, Miami poker, 2bet, Riverflop).
Let me assure you NO poker site or network wants to leave the US. The US market is to great to want to shut out. The ones that stay are at risk if owners of these sites get caught in the US they will surely be arrested. Some of the sites that did leave from the start were publicly traded on overseas markets the stock holders no matter how many shares they owned would also be at risk in the US so that is why several left.