I just upgraded to Intrepid Ibex, the latest version of Ubuntu Linux. On the positive side, I was able to get multi-monitor support running with no particular trouble. Networking appears to run both wired and wireless simultaneously, rather than leaving wireless disabled until you disconnect wired. I think I prefer the old way.
On the downside, I wound up with a recurrence of a bug I'd fixed in Hardy Heron, where the keyboard randomly goes into repeat or drops keys. I won't know if I've fixed that until I use the laptop away from my desk--the trigger seems to be hitting the touchpad and keyboard at the same time, and at my desk I use my 20 year old Type M. (Once the bug is triggered, it is also on the external keyboard)
Sound lost the right channel--Appears to be a Pulseaudio problem.
sudo killall pulseaudio
sudo alsa force-reload
fixed it for now, and it is working through logoff and logon. Took a surprising amount of time to find a solution--Lots of pulseaudio problems reported, but most are either no sound or distorted sound, I didn't find anyone who had only one channel.
Suspend now seems to work again--Suspend worked originally, (and in fact, unsuspending was necessary to wake my wireless up) but for the last two releases it would not unsuspend, and I had to hold the power button down and force a reboot.
Update: Sound doesn't come back when unsuspending.
The external mouse isn't waking up the screensaver.
Easy multi-monitor support is the only compelling feature I've found so far, otherwise I'd stick with the previous version--especially since it is in long term support.