As a million of you, I've upgrade to the new iOS5 on my iPad1 and my iPhone3GS. Since I am an Ubuntu user, I knew that I would probably loose connectivity with my devices... And it's now confirmed
Using Ubuntu 11.10, my laptop is able to see the device, but cannot access it. An error shows up saying something about the device being locked down. Now I have to be patient until the team of libimobiledevice makes their library compatible with the new iOS5.
On a good note, I am still able to tether via bluetooth.
So if you are an Ubuntu User, you might just want to wait a bit until that issue is solved.
In my case, it's not a big deal as I can rely on dropbox for most of the thing I do. But since iTunes deleted my music imported using Banshee, I need to find another way to re-import my music... A last sync with iTunes?