After one year on the same, dedicated root-server, we decided to switch to a cheaper hosting and ordered a Virtuozzo-based VHost, costing only a quarter of the dedicated server. Everthing eating up much memory or processor-time will move to a secret backend.
Guess what: Shit happens. Other than the great VMWare, the f*cking Virtuozzo doesn't support low-level-ip, so tools like nessus, hping2 or even silly traceroute won't work anymore. We'll have to switch them to another backend, too, to keep our old scriptset.
You shouldn't notice anything while the domain is in transit as both servers look mostly the same.