The first major issue after the upgrade - I had no sound. The mic wasn't working too.
First I played with the Sound System in the System Settings but nothing changed. Then I tried the mixer - I should have thought of it sooner. I unmuted some channels and voila - both sound and microphone input.
So the upgrade had played with the mixer settings. That isn't very nice experience :/
PS. Another thing that was changed after the upgrade - the default browser was set as Konqueror, but I use Firefox.