I believe the reason for this rally is silly. We would likely first need to see a major slowdown in order for QE III to happen. It would also likely cause higher commodity prices, while offering little economic benefit.
After the beating the market has taken it might be looking for any excuse to rally. I believe Europe is still the major issue. If the EU does something to stem the bleeding than we likely have seen a short term low. If not I expect this rally will get erased rather quickly.