Bad things will happen.
In vista there is a GPO called “Display information about previous logons during user logon”
Beware setting this in your environment.
If you configure this as a domain based policy you will no longer be able to logon as a domain user. You will see the following error:
As opposed to what we should see:
To recover you will need to logon as the local admin and revert the domain policy
This is by design. I expect someone to complain about this, but if there were any changes at all in this area , the most I would expect is some kind of additional wording in the GPO about “hey don’t do this in a domain until you have LH domains…” or something like that.
So I just wanted to warn you before you locked all your domain clients out.
Not sure if there is a KB on this yet... Ill look into that.