VMware seeking scale took its eye off the ball.
“The problem for VMware is that while Hyper-V started out slow, it’s catching up”
The other interesting thing, is unlike with their server virtualization platform, where they had a 6+ year head start. When it comes to the cloud PaaS environments, MS actually had them beat with Azure, and Azure is a far more mature platform for cloud services now than VMwares. For IaaS to PasS bridge that MS is working in with Azure Virtual Machines and enterprise online backups, and DR replication, I think that is the special sauce everyone will be scrambling for in the coming years.
From a virtualization management standpoint MS also has a huge lead with the System Center products. Not that everyone uses all of them, but the brand, the functionality, and the integration all exist in many environments already.