I m running on XenServer 5.5 now. It looks solid. Will have my server back on the internet on Friday. Been down for a week, I am moving.
It's been ton's of fun. Now real question how har would it be to create a kernal that is XenServer optimized for Windows and Unix Xen implementations that would be able to be used to build full blow installation packages so we could use Xen with all it's whistels and bells enabled.
RC