The glass is half-full: Why the U.S. economy will strengthen in 2010

It's been hard times for the U.S. economy. The unemployment rate essentially doubled as the economy contracted, making the recession from 2007 to 2009 the longest and worst since the 1930s.

But while long-term and structural factors are likely to weigh on economic growth in the quarters ahead, the outlook isn't all bad. Investors would be remiss if they didn't consider certain "rays of light," factors that are working in the economy's favor. Here are the major positives heading into 2010: