Like many things in technology, it depends.
Mobile device management is a great way of protecting devices. But increasingly, it misses the mark, and here's why.
As an employer, I really don't want to have control or knowledge over an employees personal apps and data, which is exactly the power that MDM gives an enterprise. In the U.S. (at least for now) this isn't a legal issue, but it's making smart enterprises increasingly queasy. Many an incident where an employee's personal data was accidentally (or purposefully) wiped has resulted in conflict between employee and employer.
Now for enterprise-owned devices, this may be fine. For employee-owned devices, this gets gray (see above). And as we think about our extended workforce, the distributors, contractors, channel partners, and other business partners that work with us but not for us, MDM is a totally unacceptable solution.
Mobile Application Management (MAM) focuses on the control of the apps and the data, rather than the device, and for this reason, is rapidly becoming a target of interest for the smart enterprise.
The entire Mobile Management space is in its infancy, so most corporations are making tactical purchases to get them through, but there's lots happening.
I've worked in data protection, mobile (MDM and MAM) and think I'm pretty even-handed on the subject, but like all things, you owe it to yourself to do your homework.
Hope this helps,