How do companies handle Apple IDs with the new iOS7 features?

My company has a number of iOS devices that it has purchased for employees to use. Traditionally we have let employees use their personal Apple IDs on their company phones/tablets so they can have access to their personal purchases, etc. It is not really feasible for us to force employees to use a corporate Apple ID as that would prevent them from accessing their personal content and there would be a revolt if we tried to implement that policy.

Now that the new iOS7 and Find my iPhone enhancements prevent you from restoring an iOS device to factory defaults without the associated Apple ID credentials, what is the recommended path for businesses to take if they are not large enough to warranty an MDM solution? If an employee leaves the company and turns in an iOS device that is password protected, how can the company restore it if they don't have the employee's Apple ID? Normally this is not a problem, but occassionally an employee leaves on bad terms and won't cooperate.

Is there a way to register a device to a corporate Apple ID, or otherwise "flag" the device as a corporate-owned device so the corporate Apple ID can restore the device to defaults while still allowing the employee to use their personal Apple ID on the device?