Internet Gambling Regulation and Tax Enforcement Act of 2009 - Amends the Internal Revenue Code to: (1) impose an Internet gambling license fee on Internet gambling operators and an additional tax on unauthorized bets or wagers; (2) require such operators to file informational returns identifying themselves and the individuals placing bets or wagers with them; (3) require withholding of tax on net Internet gambling winnings and on the winnings of nonresident aliens; and (4) extend the excise tax on wagers to include wagers placed within the United States or any commonwealth, territory, or possession by a U.S. citizen or resident.