The U.S. Department of Justice unsealed indictments against the CEOs and other high officers of Absolute Poker, Full Tilt, PokerStars and other afilliates today, for essentially, violating the Uniform Internet Gambling Enforcement Act. (UIGEA), 31 U.S.C. 5163-5167. Cite.
Basically, if you are a U.S. citizen, you cannot play poker online for money at those sites right now. I do not know whether you can cash out your funds. As I have read that the DoJ is asking for money penalties too, I doubt very much that you will be able to withdraw funds in the near future.