BigAdmin News Letter より。
* Solaris 10 10/08 OS: ZFS and Virtualization Enhancements
http://communications1.sun.com/r/c/r?2.1.3J1.2TZ.11Fzda.CB65kc..T.FapS.29nQ.DbUcEaP0
Now Solaris 10 systems can boot from ZFS and use ZFS as
their root file system. The update also includes enhancements
for Solaris Containers and Logical Domains, and support for
Solaris 10 as a guest OS in Xen-based environments such
as Sun xVM Server.
とのことです。
ZFS root からbootの時代ですかねー。