AD snapshots. They sound nice don't they?
And they sort of are.
The details on how to set them up are here:
The main issue I have is that there are no good ways to export the data into the AD. You can develop a script, use csvde, ldifde, but not really easy in times of crisis.
You should be aware that all snapshot data is read only and is, by default, only accessible to domain and enterprise admins.
The Directory Service Comparison Tool does provide a nice interface to doing some of these things. The only issue I had with it is that after loading the snapshot and the AD, it didn't show any changes that had occurred in the live AD since the snapshot.
Now, this may be me, but I haven't seen anything on t'internet that tells me otherwise.
It will pick up any changes that you make to the AD while the mounted snapshot is active.
You can then reanimate and restore attributes.
However, if it can't tell me the initial differences between a snapshot and the AD, it ain't no good to me as it would have to be running all of the time otherwise.