So, yes, preupgrade is in the F8 repos now, and that’s nice. But it’s not 100% complete and that’s why it’s not in the menus or anything yet.
The current version – 0.9.3-3 – will fail to boot the installer if your /boot directory is a) on RAID1 (#444497), or b) on your root partition (#446826). These should both be fixed in the next preupgrade release.
At the moment, though, there’s a bug that prevents preupgrade from being able to finish any upgrades without a network connection. This is the bug that Greg hit during his preupgrade. Luckily, as he noticed, you can bring up the network in the installer, but you can’t use anything fancy – no wireless, no VPN, etc.
This may not be fixable without a respin of Fedora 9 (or, at least, a custom stage2.img specifically for preupgrade). I’m not really happy about it.
Hopefully we can do this right for F10. Sigh.