In a WPMU multi-site setup, have a client's site finished and want to point their DNS to my servers. Problem is, they have a live site already at another host. I want to do it with no down time, of course, since they get traffic.
I've seen hosts before who did something where I was able to change the DNS on the domain to the new server, but the host pointed it back to the old host until I was ready. Once I was ready, they'd do something and the switch would be instant.
Is this possible within my WPMU admin, and, if so, can you tell me how? I'm hosed at pSek.