Can anyone elaborate: why all these cloud webhosting people are taking legal risks of Oracle changing license for (Open)Solaris or closing this OS project entirely, legal risks of being sued by Oracle for patent infrigement / whatever else legal bullshit?

They could just port KVM to FreeBSD instead; FreeBSD already has ZFS, DTrace and all other necessary bells and whistles for cloud webhosting infrastructure. But in contrast to (Open)Solaris they have community support for new hardware, a lot of already working drivers for existing hardware and also much safer legal position.

Are there any technical difficulties with porting KVM to FreeBSD? Can anyone elaborate?