I wrote a little script (attached) that creates a sarge chroot, installs all packages of standard or higher priority, and then upgrades the whole thing to etch.
I've just ran it, and with the exception of lpr, there were no problems. lpr does cause a problem, but it seems to be because the chroot does not contain /proc and the preinst that runs on upgrade calls start-stop-daemon, which fails due to the lack of /proc. So, in the real world, I don't think there's a problem. I attempted to install all optional packages from sarge and do the test with them, but that failed: it seems not all optional packages in sarge are co-installable. Should I run this regularly? Maybe improve it in some way? -- Wolfen one, you are my midday moon and I your midnight sun.
debian-upgrade-test
Description: application/shellscript