The server upgrade was started on time last night and all the websites are currently being backed-up for transfer to the new server.
Unfortunately, we do not know how much longer it will take to complete, it could be minutes it could be several more hours.
Our suggestion is that you try to avoid doing updates to your sites during this time as the changes you make may be lost during the changeover.
We will do what we can to help eliminate any losses once the transfer is complete and there should be very minor disruption.
Your website is still live and running during the process, there should be little or no actual downtime.
I will keep you updated as we go.