Well, if you're consolidating by replacing five vendors with one, that can have cost savings in unified billing and administration alone, and simplified environment management - one stop for all your server needs - is indeed another benefit.

I've been a contractor for a firm that still runs their own mainframe for data transformation, and had Cisco experts on the payroll. They ran their own vCenter instances integrated with their Active Directory, so moving with them to Vblock was painful mostly in giving up control.