My server will be down for a bit. I'm moving it to the fiber optic network in a few minutes (which should be fast), but the DNS has a TTL (Time To Live: How long until the DNS caches around the world hold onto the DNS info since their last look-up) of 24 hours.
So for some, the change will be instant. For others, not so much.
[UPDATE: Network moved. DNS updates made. Just waiting for the DNS changes to push out.]