Re: There's a theme here
You're definitely right that there will be more migrations but BCOM doesn't care. They know the cost of migration is very expensive for the largest customers. BCOM is counting on their largest customers deciding the licensing costs are still a lot cheaper than conducting a hypervisor migration. At that point, those customers will look to remove 3rd party products that have similar functionality to the entire VMware stack (such as monitoring) and leverage as much of the VMW stack as possible to reduce cost.
The bulk of migrations will be from smaller customers that, again, BCOM doesn't care about. They're happy to let them go and focus on the big boys. There is a lot of opportunity there for other hypervisor vendors and migration services. I also think there is a huge opportunity for someone to develop automated migration tools.