During the install, it asked me where I wanted to install GRUB 2, the program that actually boots the operating system. Without GRUB, nothing happens. Alas, the "help" file provided is a bit confusing; it made it sound like I was supposed to install GRUB to /dev/sda1, so I did. The upgrade process finished, the machine rebooted and... GRUB error message and a recovery command prompt. Great. Did some Googling and finally found a webpage that gave instructions on how to fix it.
First you have to boot to a Live CD. Easier said than done. Apparently many of the USB cables I have around here are crap because my external CD drive kept flaking out. I finally located a good cable and got Ubuntu
For those who are interested, the exact command list is:
sudo fdisk -l
sudo mount /dev/sda1 /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo chroot /mnt
(optional, only if you're on Ubuntu/Debian) apt-get install grub-pc
grub-mkconfig -o /boot/grub/grub.cfg
grub-install /dev/sda (try grub-install --recheck /dev/sda if it fails)
Ctrl+D (to exit out of chroot)
sudo umount /mnt/dev
sudo umount /mnt
So I finally got Ubuntu back up and running, only to discover the netbook interface had been forced upon me again. Originally they had an app for switching between the netbook desktop and the classic desktop, but this was removed with Koala, but I was still able to manually disable it. With Lynx, however, they locked out the procedure that I'd used before. (When did Steve Jobs start working for Canonical?) I spent another hour or so before I discovered you switch to the standard GNOME desktop by logging out and selecting it from a menu that appears at the bottom of the screen while you're typing in your password.
GNOME boots up this time... but the desktop panel is completely blank. There isn't even a button to shut down. So I set about trying to rebuild the panel, then had to spend an insane amount of time trying to figure out where the networking icon disappeared to. It's part of the Notification Area applet, naturally. Obvious and Ubuntu are two words you never find in the same book, let alone the same sentence.
And then I discovered that the upgrade program uninstalled Pidgin (and deleted all my settings) and tried to foist Empathy on me. Gee, thanks. Got that straightened out. There's some pretty annoying features with Lynx, like being unable to configure some of the icons on the desktop panel and being required to use some programs like Evolution. (Jobs, is that you?)
I think I've got everything working again, though I tried setting up Gwibber and it didn't appear to do anything. Ubuntu used to be getting better with each release, but I think they took a real step backwards with this one.