"As you may know, Active Directory relies on DNS. It relies on DNS to the point that if you don't have a DNS server when you first create AD it prompts you to make your first Domain Controller a DNS server. Since a lot of folks set up their network with defaults, that means there are a heck of a lot of Domain Controllers out there vulnerable to this, which means not only would an evil net gremlin have access to your server, but they'd have access to some of the most sensitive information on your network, including the (highly encrypted) database that holds all your user information."
I just started using stumbleupon and look at what I stumbled upon! Guess its time to lock up RPC and hope you don't have to do any administering remotely.
Microsoft does add some tips for preventing the exploit, but unfortunately they all have to do with locking down the RPC service on the server, which means you'd have no way to do remote administration.