I "upgraded" a server from RH9 to CentOS remotely, as from WBEL 3.0 to CentOS 3.0, and a RH8 to CentOS 3.0.. Used YUM to do it.. HOWEVER, it was (basically) Redhat - > Redhat (based) upgrade. I have no idea how well it would work to do a Deb box that way. Maybe build a local box (or VMWare image, that way you can use the Snapshot to recover screwups), with Deb on it and try the "upgrade" .. See if it bombs out.