I'm in the process of moving DNS, email, the database, and the site itself over to the new machines. Pretty much in that order. I'm trying to do it in a way I think makes sense and will minimize disruption and the amount of downtime. Undoubtedly I will fail, and the site will be unreachable at that time. In the meantime, rstevens has been kind enough to set us up with a temporary forum over at Dumbrella to which you can post descriptions of any of these disruptions as they happen. Hopefully that will allow me to get the site up and running again faster than I could otherwise.
UPDATE: Current plans are that at some point very early tomorrow (May 8) there will be mega-downtime as I move the database over to its new home. DNS records will be updated to reflect the new servers at approximately the same time. Assuming all goes well, next week I'm going to be auctioning off some of the old machines, so anyone interested in 1999-era hardware can look forward to owning a piece of Goats.