I was wondering if it is best practice to add the Hyper-V host to the domain or leave it standalone? I have two Win2k12 VMs that will be getting added to the domain.
In a cluster it is best practice to add the hosts to the domain. Microsoft introduced a new feature called active directory-less cluster bootstrapping in 2012 that allows for your hyper-v cluster to come up properly even without AD being present at bootup.
Yes, it makes it a lot easier to manage and deal with the host as you get the normal AD permission goodness.
That said, buildout another OU for hosts so that you can change which GPOs get applied. Typically you will not want to apply the same policies as other machines.