I think everyone needs to take a "reality pill" and realize that if the US government decides (for whatever reason) to put an end to online gambling, they likely can. Some in this thread have argued that because the online sites are licensed in [Costa Rica, Isle of Man, Canadian Indian Reservation, etc.] that they are immune from US law.
I think anyone holding that belief should read Chuck Humphrey's essay,
Where are you? Here! which discusses jurisdiction issues. After reading that article, I'm convinced that any US court (federal or state) could assert jurisdiction against any online site serving customers within the court's jurisdiction. [Note: I'm not an attorney, but Mr. Humphrey's arguments were persuasive to me.]
I think that Bill and Oliver are likely correct about what this means. While I think that the very long-term future of online gambling is good, I would not be surprised to see an effective prohibition in the near term. The U.S. has been getting $0 in tax revenues from the online sites. The sites aren't licensed in the US. These two factors likely make the outcome clear.
-- Russ Fox
co-author, "Why You Lose at Poker"