Once the US opens up, several items will occur:
(1) More players, which means more industry dollars overall. Marketing will play a huge factor here.
(2) The big operators will come here. I don't care how tainted some of the bigger players in the business are. History repeats itself. They will buy their way into the US market.
(3) Taxes are an interesting dynamic. In Vegas, unless you win a super progressive slot, no IRS officer is advised of your winnings. The reason is simple; if the US government takes an aggressive tax stance on Vegas players, they kill Vegas. I believe the US government may lay low at the beginning on the players to encourage more action. They will tax the companies that are making profits.
(4) Offshore companies that are savvy will do well. BUT, known respected brands in the US over time will do better, provided what I said above about not taxing the player is true. The player will go to a place he/she can trust.
In any event, this is a fantastic development for the gaming industry.