Virtualization ready for serious tire kicking...
With Red Hat's announcement, Xen based virtualization is now available pretty much anywhere you'd want to use it. In addition to many/most variants of Linux, Solaris also is enabled for use in Xen's domain 0. There is still some work to do in mainline with paravirt_ops to make any linux kernel easily or trivially configurable for use as a domU (guest) operating system but most of the work for paravirt_ops initial uses is complete.
For those looking to consolidate workloads, test new environments, rapidly prototype new workloads, and perhaps even experiment with application containers, this is a good time to do so. From here on out, virtualization should just get easier and easier to use on Linux.