The specific use case that VmWare is pushing is more from an isolation point of view.
More and more people are using their smart phones as "the one device that does it all". From a security point of view, most IT departments prefer isolation between your work phone and personal phone.
VmWare is aiming to satisfy both by providing isolation and a single smartphone.
This should appeal to the IT admins who can then control the business phone vm to whatever levels of strictness while not bothering with the personal phone vm on which the user can load up Angry Birds or pics or Facebook.
Since there is isolation, it would be extremely difficult to mistakenly share confidential documents into Facebook.
Also, work vm can be provisioned and wiped independent of your personal stuff.
If you change jobs and you don't need to surrender your smart phone - your old company's IT just de-provisions the work vm remotely and you're on your way to the new company, where the new IT provisions a different VM.

I'm waiting for the phone that has enough juice to do this without making me want to throw the slow piece of s*** out the window.