Good news or gaffe?

That's what I'm wondering about what Mankiw said (hat tip: The Note.). NYT's first paragraph:

Calling the current system of Social Security benefits unsustainable, a top economic adviser to President Bush on Thursday strongly implied that any overhaul of the system would have to include major cuts in guaranteed benefits for future retirees.

Is this predictive of Administration policy or is it Mankiw speaking a truth the White House would rather not discuss, like when he praised outsourcing? Both?