I just ran the upgrade via the script. Before I report on what ahppened, here's my hardware details. I have a custom built box with:
* Intel D845GLVA mobo with onboard networking
* Intel Celeron 2.20GHz processor
* 766MB RAM
* Nvidia GeForce2 MX/PCI graphics card
* 1.0-9639 Video drivers installed via Envy
* Ubuntu 7.06 Feisty Fawn
The starting kernel is 2.6.20-16-generic.
I ran the update script with no problems. I then used Envy to remove the Nvidia driver, then manually added the Gutsy repo and added the Nvidia driver with Envy. Once that was done I manually removed the Gutsy repo, crossed my fingers, and rebooted.
The xserver failed, but I ran Envy from the prompt (text version) and reinstalled the Nvidia driver, rebooting when it was done.
Once I rebooted all was well, and I'm now running the 2.6.22-generic kernel. I did get a notice of 5 KDE updates being available (I run a few KDE apps, including Anorak), including the kdedesktop (from 4:3.5.6-0ubuntu20.2 to 4:3.5.6-0ubbuntu20.4) for some odd reason, but details aren't available yet so I'll hold off on accepting them for now unless someone lets me know they're ok to take.
Boot up seemed a little quicker, but I was getting another cup of coffee and forgot that's the first place I'd see a speed increase so I'll have to post again later to say if I'm noticing a difference. An excellect script, definitely deserving to be in the Best of Ubuntu list. Getting this done makes me even more eager to grabbing the Gutsy upgrade when it hits beta, hopefully on Thursday.
One other note: I hadn't known to set my /home up on a different partition when I first made the switch to Ubuntu and when I was moving it over the weekend I ended up borking things and had to reinstall Feisty so the install is pretty cleaned up from where it was late last week, so any speed improvements from the new kernel may actually not be as noticeable, or at least I may not realize the speed improvements are from the kernel and not just cleaning things up.