When we launched the new site we also upgraded the server that runs HostNexus to an awesome Core2Quad Xeon X3360 with dual 15k RPM SAS drives and 4GB Memory. The old Pentium served us well for 5 or 6 years with perfect uptime (except for when the data center blew up last year) but it was time for an upgrade. But anyhow, I digress.
Changing servers, changing hosts, same deal really and for about a month I had parts of HostNexus running on the new server with the majority ruinning on the old server and when it came time to switch we did so and the whole propagation process took a whopping 5 minutes.