Thanks for the detailed response!
I certainly agree that there are incredible advantages to using Solaris over other flavors of UNIX for virtualization and management tasks. The biggest value-add Solaris provides (for me) has been and continues to be ZFS. To that end, I suppose my criticism here centers around some of the limitations in tapping into the power of ZFS directly for virtualization. It seems it's a catch-22 in my case: If I want to use the Oracle Hypervisor in Solaris, I am limited to Solaris as an OS, but I can use local ZFS pools for my instances and zones. If I want a mixed OS environment, I would need use OracleVM (XEN) or some other HyperVisor (KVM, ESXi, HyperV), but I then lose all the cool ZFS stuff, native to Solaris.
Joyent has been doing some interesting things with their port of KVM to Solaris, but it's not 100% perfect either, as it it limited to older ZFS versions, doesn't work with all CPUs, and only allows you to use local storage for VMs.
Regardless, it's very exciting to see all of these technologies coming together, and I am looking forward to what future enhancements will be forthcoming in 11.3!