I imagine it's more common to be underutilized or misapplied. Humans tend to grow and change much faster than their corporate job descriptions can keep up with. There's always a mismatch, it's just a question of whether or not the key players acknowledge it - and of how much indulgence is afforded to the employee in terms of personal growth that may not perfectly align with current business objectives.
Google apparently has a system in place for enabling this truest form of employee engagement:
Google has set up an environment that makes it pretty easy for people to transfer between groups, and even between sites. You have to be a grown-up about it, of course, and not ditch your team during some critical crunch time. But provided you exercise mature judgment in the matter, you can pretty much switch teams whenever you want, and it doesn't cause the company to grind to a halt, as such a policy would at other places I've worked or visited.
