In fact, he's been golfing. He received a counterterrorism briefing early this morning, Hawaii time, and moments later, left for the gym. The president's vacation activities might have become the subject of a fierce partisan fight -- but really, the only carping is coming from the usual suspects on the right.
There is a reason why Obama hasn't given a public statement. It's strategy.
Here's the theory: a two-bit mook is sent by Al Qaeda to do a dastardly deed. He winds up neutering himself. Literally.
Authorities respond appropriately; the President (as this president is want to to) presides over the federal response. His senior aides speak for him, letting reporters know that he's videoconferencing regularly, that he's ordering a review of terrorist watch lists, that he's discoursing with his Secretary of Homeland Security.
But an in-person Obama statement isn't needed; Indeed, a message expressing command, control, outrage and anger might elevate the importance of the deed, would generate panic (because Obama usually DOESN'T talk about the specifics of cases like this, and so him deciding to do so would cue the American people to respond in a way that exacerbates the situation...
Let the authorities do their work. Don't presume; don't panic the country; don't chest-thump, prejudge, interfere, politicize (in an international sense), don't give Al Qaeda (or whomever) a symbolic victory; resist the urge to open the old playbook and run a familiar play.
In a sense, he is projecting his calm on the American people, just as his advisers are convinced that the Bush Administration projected their panic and anger on the self-same public eight years ago. It's a tough and novel approach -- and not at all (as they say in Britain) party political -- because the standard political script would have the President and his Attorney General appearing everywhere as soon as possible.