(updated below - Update II)

For much of the day yesterday, the featured headline on The New York Times online front page strongly suggested that Muslims were responsible for the attacks on Oslo; that led to definitive statements on the BBC and elsewhere that Muslims were the culprits.  The Washington Post's Jennifer Rubin wrote a whole column based on the assertion that Muslims were responsible, one that, as James Fallows notes, remains at the Post with no corrections or updates.  The morning statement issued by President Obama -- "It's a reminder that the entire international community holds a stake in preventing this kind of terror from occurring" and "we have to work cooperatively together both on intelligence and in terms of prevention of these kinds of horrible attacks" -- appeared to assume, though (to its credit) did not overtly state, that the perpetrator was an international terrorist group. 

But now it turns out that the alleged perpetrator wasn't from an international Muslim extremist group at all, but was rather a right-wing Norwegian nationalist with a history of anti-Muslim commentary and an affection for Muslim-hating blogs such as Pam Geller's Atlas Shr....  Despite that, The New York Times is still working hard to pin some form of blame, even ultimate blame, on Muslim radicals (h/t sysprog):

Terrorism specialists said that even if the authorities ultimately ruled out Islamic terrorism as the cause of Friday’s assaults, other kinds of groups or individuals were mimicking Al Qaeda's brutality and multiple attacks.

"If it does turn out to be someone with more political motivations, it shows these groups are learning from what they see from Al Qaeda," said Brian Fishman, a counterterrorism researcher at the New America Foundation in Washington.