The general consensus among economists is that the Fed will finish up their mad money printing scheme (QE) and start to raise interest rates by sometime in 2015
I don't think this premise is correct. DeLong, Krugman, and Summers are Economistis, and influential ones at that. They probably wouldn't agree, so this isn't likely a consensus. Yellen has a lot in common with them, in terms of thinking, and chairs the Fed. So they might be a bit more likely to be correct than people who disagree with them on this point.
Look up Summers' secular stagnation hypothesis. It's getting traction in liberal policy circles, and argues for very low rates for potentially a very long time. Thinking about employment might also be wrong. Inflation might be the real trigger. >= 2% at current targets, but there's some thinking that the current targets might be too low.
End of QE will not necessarily mean a rate hike is imminent.
BTW, economists disagree about whether or not it is a valid role of the Fed to try to pop bubbles. Yellen is suspicious of the notion, on the grounds that it's hard to identify a bubble with a high degree of confidence. I mention that because bubble vigilantism is another reason one might think the Fed would want to raise rates.