Is company quarterly guidance necessary?

The U.S. economy falls into a recession, a global financial crisis ensues, triggering a slowdown in global growth, then an outright global recession. Almost on cue, companies begin to scrap guidance -- or their quarterly and full-year outlook for revenue, earnings and other metrics -- and the debate on the merits of guidance begins.

Is guidance superfluous, an unneeded metric on an already overloaded financial landscape? Or is the elimination of guidance another step into opaqueness and a lack of transparency -- just an extension of the clouded climate that's in part responsible for the financial crisis in the first place?