Wishing this won't happen again, but if it does, do you think it would be beneficial to point the members to the status pages for the hosting site? It's not that difficult to find who the host is, so I don't think you will be releasing any secrets, but it might be useful to the forum members.
Or, is there someplace else that members can get a status update, short of everyone sending you an e-mail? Maybe a temporary or unused site somewhere? The main home page appeared to work long after the logon page went down. Is that on the same server?
Overall, the new host, IMO, is a lot snappier than the previous ones.