I upgraded my laptop (Lenovo x300) to Ubuntu 8.10 a few weeks ago. The rumour was that power management was better, and I was longing for a kernel that handled the sound on the x300 without a re-compile of the driver every time I updated the kernel.

The upgrade went smoothly, although it took a very long time. The default Ubuntu mirror for Canada seems to be very slow these days. (I've since switched to http://gpl.savoirfairelinux.net/pub/mirrors/ubuntu. It seems a lot faster.)

Two things I've had to work on. First, suspend and resume screws up the wireless until you add a line to /etc/pm/config.d/00sleep_module. First, you have to figure out which driver you're using for wireless. Do
lshw | more
Look for the line that says "wireless" by typing "/wireless" to the more prompt. Then look for the next line with "driver" in it. In my case it says "driver=iwlagn". So now edit the file and add the required line:
sudo gedit /etc/pm/config.d/00sleep_module
Add the following at the very end:
The other problem was more mysterious. CBC Radio's website wouldn't play after upgrading to 8.10. It had worked for my in 8.04 after some fooling around, but I couldn't get it to work. I had given up after wasting almost a whole day on the problem. After a few software upgrades, it started to work. For the record, I'm using gnome-mplayer to play Windows Media Player material.