minimally installed F9 system.  yum install preupgrade.  run preupgrade

Fail:  
Traceback (most recent call last):
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 19, in <module>
    import gtk

Cheat and just install system-config-netboot to get these things (and who knows what else), so next:

Fail:
Traceback (most recent call last):
  File "/usr/share/preupgrade/preupgrade-cli.py", line 26, in <module>
    import preupgrade
  File "/usr/lib/python2.5/site-packages/preupgrade/__init__.py", line 27, in <module>
    import xf86config
ImportError: No module named xf86config

Install pyxf86config.x86_64

At this point its just pissed that it has no fonts, but at least it "sorta" starts.