I thought of this too. They did it with much smaller outage a few weeks ago, so I don't think it would be a bad idea.
I suspect most of the issues reported here are from the migration? Perhaps you should freeze posts and put a top sticky with just official updates?
Just get us a magic button that goes next to (+ Reply To Thread): (+ Reply with link to Updates topic in News/Announcements)
That'll work
I take a step to reduce the numbers of support threads. You can see it in my signatures
This gave me an idea - don't know if it is possible because I know nothing about the v Bulletin back end.
Is it possible to insert a banner in the header? If so, a simple banner with wording similar to the first two lines of Zubair's signature (including the click link) could be temporarily placed in the header. No matter how you enter the forums and or page you visit you would see this at the top of the page.
Is this even possible in v Bulletin?