Earnings Preview: General Electric, a Bellwether

With all the back-and-forth between NBC talk show hosts Jay Leno and Conan O'Brien over who is the rightful heir to the late-night slot, you'd get the impression that General Electric's (GE) main businesses is a television network.

It's best to keep a sense of perspective: GE, a closely-watched industrial giant, reports fourth-quarter earnings Friday before the market opens, and the company is a virtual mutual fund in one company -- and a good gauge of the health of the U.S. economy.