He's widely expected to say that the gas pedal remains press down for the foreseeable future.

Ben White at POLITICO passes this along in today's Morning Money newsletter:

HFE’s Jim O’Sullivan: “We expect the message on Fed policy, including QE3, will remain ‘full speed ahead’ in the FOMC statement and the chairman’s press conference today. Officials will have to acknowledge a pick-up in growth in Q … and they may tweak the wording on QE3 slightly, but the end result will likely be no deviation from current policies and no hint that a scaling down in the pace of easing is imminent. The main reason for continued easing: The unemployment rate remains ‘elevated.’”