The good news is that mobile device management tools are well proven in all sorts of industries, including highly regulated fields such as health care and financial services. There are simple ways to handle tech support for the new generation of mobile devices; plus, it turns out that iOS devices at least are cheaper to support than the traditional BlackBerry. One lesson SAP learned is instructive, and I've heard the same finding from vendors offering mobile support tools: Issues around 3G and 4G cellular networks -- slow speed and inconsistent availability -- form the bulk of employee support questions, even though IT can't do a thing about the carriers' networks. What IT can do is educate users that cellular networks aren't as reliable as corporate networks and design apps to better handle latency and intermittent connections.
The bad news is that the MDM tools don't handle the whole picture. MDM tools work mainly with mobile devices that access corporate email, whose servers validate devices and apply management policies to them. But MDM tools don't address devices on the corporate network that aren't accessing email (nor those accessing email only through Webmail), so effective BYOD management also needs to involve the network in a way that goes beyond the traditional "unguarded inside the building" approach practiced by most organizations.