Big vSphere shops with large investments in vSphere should stay in their private datacenters. It's not worth migrating everything.
If they want to innovate. They can move to IBM SoftLayer + VmWare on top, which is allegedly a solid offering, while keeping their ways of doing things.
Why should they remain in their private datacenters? In AWS they have access to a wealth of platform services like fully managed relational and NoSQL databases, autoscaling, resilient queueing, data movement, analytics, and data warehousing services.
The value in migrating is that you get access to the same VMware hypervisor and ecosystem, but now you have access to a wealth of new data services that are fully managed and much lower cost than building your own.
I know this is hard to believe, but in the early 1900s, any large business had a power generator in the basement, because the power grid was unreliable and daily outages were common. How many businesses today have their own power generators? In 2050, how many businesses do you think will have their own datacenters?
If they want to innovate. They can move to IBM SoftLayer + VmWare on top, which is allegedly a solid offering, while keeping their ways of doing things.