Yesterday I thought let's play with FC12 (aka Rawhide, aka FC11.90). So I enabled the Rawhide-repositories on my FC11 laptop and entered "yum -y update". And after a while it was there... bleeding edge kernel and other packages.
The first issue I run into, was that Firefox 3.5 was not able to run, it caused a segfault. There seems to be a bug in the xulrunner package. So I was able to fix it, by "downgrading" Firefox to 3.0.11, but that one crashed on pages using "Adobe Flash plugin". So I removed the flash plugin, because I wanted bleeding edge Fedora. So having that "sort out" I wanted to suspend my laptop, and guess what... It didn't want to suspend... so after some hacking around... it still didn't work.
So my final decision was Go back to FC11. I was able to "downgrade" my system in about 60 minutes. At home I've a mirror repository with al the backups, so during installation I added these repositories, so I also had all the updates in one go.
Lesson learned: "Bleeding edge... is indeed bleeding edge!"
I need my work for my daily work... If I won't need it for my daily work I would have keep FC12 (aka Rawhide, aka FC11.90) on it to participate in developing FC12.