I upgraded from Hardy to Intrepid on my work laptop, a few weeks ago. Apart from ssh-keys not working through the keymanager (again) and Firefox starting up with the window title outside of the screen I’d say it all went pretty smooth. I had some problems with our backup solution, but it turned out that it had nothing to do with the upgrade.
I solved the keyring problem by deleting the .gnome2 folder in my home directory. This could most likely be solved a lot easier but I didn’t have the time to dig deeper at the time. Changes have been made to the Networkmanager which now supports mobile internet connections. So far I have not successfully been able to connect to my provider using this new functionality so I’m sticking with the wvdial method.
A really annoying new thing with the network manager is that it shows all my interfaces with static ip-addresses from /etc/network/interfaces. So what? Well if you’re running a lot of systems with dedicated “Host interfaces” in Virtualbox, I guess you see what I mean. As a bonus, each time I attach the network cable it tries to bring up one of those virtual interface with a static ip instead of the eth0 interface… Luckily I’m using 3g and wi-fi a lot, otherwise I would have to face facts and fix the problem 
Hopefully something that can be configured better. I haven’t bothered to look at any documentation, things should just work . Perhaps an alternateive strategy by dynamically creating interfaces when starting Virtual boxes, leaving the interfaces file and ifconfig output cleaner.
