I've always said that macroeconomics was a voodoo discipline.
Now, one of the field's best admits it. Really, all the important macro research was done by Keynes, a handful of behavioral economists, and some academic interlopers who didn't drink the math-heavy kool-aid. Economics, to be a science and not voodoo, needs to return to empiricism - which means the bubble of 2008 and other real world phenomena need to be taken into account and not ignored as aberations.
A bracing read: http://www.nytimes.com/2009/09/06/magazine/06Economic-t.html?_r=1&em
Here's another critique from one of the field's best: