The big difference is the willingness of the Fed to announce another round of quantitative easing, which would be QE4. The low unemployment rate has convinced many Fed governors that the U.S. economy is about to take off. The ISM reading contradicts this belief. As well, many believe that the European Central Bank will ride to the rescue by adding to its own QE program. The problem with this logic is that ECB QE will weaken the euro and strengthen the U.S. dollar. A strong U.S. dollar is likely to weigh further on the U.S. manufacturing sector.
Up to this point, investors have been correct to believe in the rock star central banker, it's been one heck of a show. However, as one rock star leaves the stage the next act may not live up to the hype. Given the inevitable impact of a strong dollar, the next act may get booed off the stage. Sorry Mario.