Each mutant possesses a special skill which has its own inherent value. Because of this, a mutant can be viewed as a craftsman or a skilled laborer. Mutants with enhanced strength can work in construction, demolition, or even transportation. Storm could irrigate the crops of all the suffering farmers in the midwest and California when the droughts of summer are destroying their crops. Quicksilver could sort the daily mail output of the United States in 3 hours. And the extraordinary power of these abilities would only make the economic effect of using mutant powers that much more extraordinary itself. Time, labor, and machinery costs would all be cut dramatically.
Tragically, most mutants use their powers to either save the world or terrorize it. At least this is the popular depiction in Marvel Comics. Imagine what Magneto could do if he worked in construction. For one thing, all of those New York City public works project would have their completion dates moved up from 2018 to roughly five minutes from now. But instead, he spends his time sinking Russian submarines and making asteroid bases to live in. For the love of God, the man has the power to build himself a high-tech home in space. He could repair the Hubbell telescope with no trouble whatsoever.
The only time Marvel Comics presented a mass use of mutants for economic purposes, it was in the context of the island nation of Genosha. On this island, mutants were enslaved and forced to work for the government. This turned the troubled economy of Genosha around in the span of a few years, making it a thriving paradise (for those who were not enslaved and constantly tortured, of course). Naturally this brutal treatment of mutants could not stand and the X-Men destabilized the government (resulting in thousands of deaths, but that is the price of freedom and giant, bloody splash pages). Eventually Genosha became a haven for mutants. And with an all mutant population, the island did thrive, but in total isolation from the rest of the world.
But its strange how there haven't been any depictions of how mutant powers could be integrated into the modern economy. It seems like whenever mutants are given employment, it's usually because their powers can be used to murder someone. The government has an endless parade of mutant assassins at their disposal, yet somehow refuse to employ Scalphunter as a computer mainframe manufacturer.
Of course, there is the very logical reason why mutants are not integrated into economy in comic book stories. No-one wants to read 22 pages of Colossus moving girders to build an office building and then going home to watch "24." An ordinary, integrated life for mutants is not interesting. But tearing the head off a Sentinel while falling through the atmosphere. Now there's something special.