Upgrade process from FC3 to FC4?

[TGS]

Ha! I have a machine that I have updated from 
RH7->RH8->RH9->FC1->FC2->FC3 - with all the updates in between - 
including many development updates throughout that cycle. It is never a 
fresh install.

In fact I have migrated to a few new versions of the actual hardware, 
from a Gateway - PII-133Mhz to a Shuttle XPC - AMD XP 3000 that it 
resides on now. I also have upgraded the hard drive, by copying over 
the install, and moving from LILO to Grub.

I only have had to compare the list of installed RPMS from time to 
time, to see what RPMS are on the machine that I need to manually 
remove. That was made much easier with the yum list extras command.