Daniel Engber, writing in Slate, argues that the wind chill ought to be discarded on the grounds that most people can gather all the weather data they need simply by looking outside and, somewhat more satisfyingly, that the wind chill is ultimately meaningless:
The language of "equivalent temperatures" creates a fundamental misconception about what wind chill really means. It doesn't tell you how cold your skin will get; that's determined by air temperature alone. Wind chill just tells you the rate at which your skin will reach the air temperature. If it were 35 degrees outside with a wind chill of 25, you might think you're in danger of getting frostbite. But your skin can freeze only if the air temperature is below freezing. At a real temperature of 35 degrees, you'll never get frostbite no matter how long you stand outside.
That's all very well and good, but Mr. Engber leaves out the important reason that we ought to keep the wind chill around: it helps those of us in the Upper Midwest feel like we're tougher than everyone but those poor suckers who live in Irkutsk.