I’ve just upgraded one of my development machines from running Fedora Core 1 to Fedora Core 2 using yum.
This was a pretty painless procedure, I followed the instructions given at http://www.brandonhutchinson.com/Upgrading_Red_Hat_Linux_with_yum.html
The system feels a lot faster now (I don’t know if it’s just me or if FC2 is actually faster). I’m going to leave it a couple of days and see if it remains stable. If it does, I’ll consider upgrading to FC3.