From its write-up of Obama's address last night [emphasis added]:
Mr. Obama's speech was an effort to rebut detractors who say the administration's response to the oil gusher has been ad hoc and ineffective. He chose a setting almost always reserved by presidents to discuss war or crisis.
Unless you count when Ronald Reagan addressed the nation from the Oval Office to discuss the economy in 1981, his candidacy for re-election in 1984, Independence Day in 1984, and his Supreme Court nomination in 1987. Or when George H.W. Bush addressed to nation from the Oval Office to talk about a federal budget agreement in 1990, and his CIA director nomination in 1991. Or when Bill Clinton spoke from the Oval Office to discuss his economic program in 1993, and his balanced budget plan in 1995.
UPDATED: Politico also get its Oval Office history wrong.