Greg Ip puts QE3 in perspective:

Between the ECB’s action last week and the Fed’s today, the world’s two most important central banks are bringing unprecedented resolve to bear on economic growth. The world may one day look back and conclude the first half of September was either a turning point for the global economy, or the final nail in the coffin of the doctrine of central bank omnipotence.

Judging from Bernanke’s comments ... he waited far longer than a more autocratic chair might have deemed necessary. Indeed, he noted that the consensus across the FOMC was so broad, that “even as personnel changes going forward, this will be seen as the appropriate approach and we will have created a reserve of credibility we can use in subsequent episodes.” That line was probably the most important statement of the day, as it provided a glimpse of Bernanke’s strategy for addressing the intense and continuing criticism of the Fed: Build as deep and broad a consensus for aggressive Fed action, so that the Fed’s audiences will come to concur that the course of action is “appropriate”—even after Bernanke’s term as chair ends. Such confidence might be premature, but it suggests the hard challenge Bernanke has faced in leading the Fed in a polarized political environment marked by pockets of deep distrust of the Fed.

Dave Weigel rounds up the typically vague Republican outrage about QE3. Ron Paul, meanwhile, describes some more vivid concerns for the American people: