Microsoft has just taken a swipe at VMware's young cloud business.
VMware markets that effort, vCloud Air, as the perfect cloud for VMware users, because it just looks like an extension of vSphere. Spinning up servers in the cloud, or shunting workloads around between servers, works just like doing those chores in your own bit barn.
Virtzilla also offers a disaster recovery (DR) service in vCloud Air, because DR is such a blindingly obvious application of the cloud but also because the end-to-end vSphere story works well there too: if you're going to fail over you might as well fail over into the same environment you already operate.
Microsoft makes pretty much the same arguments when chatting to Windows users about its Azure Site Recovery (ASR) service, which shunts on-premises VMs into Azure, keeps them in sync and allows failover to cloudy operations if your bit barn borks.
But now it's making the same pitch to VMware users by making it possible for Virtzilla-styled VMs to sync to, and run inside, Azure.