Well....most of the election models that are based solely or primarily on economic fundamentals predict an Obama loss. So if he wins, I don't think it will be because of the economy.
Here are some examples:
Analysis of election factors points to Romney win, University of Colorado study says | University of Colorado Boulder
The Bread And Peace Model Says Obama Is Toast In November - Business Insider
Looking back historically, economic conditions (even with what you might consider improvement....and "improvement" is a real stretch) like this have hurt incumbents. As far as the current economy - according to the polling, most people don't think it's getting better, people overwhelmingly feel the country is moving in the wrong direction, etc.
IMO, Romney not being ahead in the race right now is because of other things (and I could list a million)...