Running KDE, with Intel graphics.
This was a weird update for me. Upon rebooting, my custom wallpaper was gone, replaced by one of the default wallpapers, and my 2 panels were missing. I got the wallpaper back easily enough, but I couldn't get the panels to show, nor could I add a new one.
Eventually, after playing with themes, toggling compositing, and changing OpenGL versions, and rebooting each time with no success, I killed and restarted plasmashell:
...and my panels were back, plus the new one I had tried to add but couldn't see. It's fine now, and survives reboots. I'm not sure what happened, but I was thankfully able to get it sorted pretty quickly.
Also, my first 3 or 4 logouts didn't behave as expected. Instead of presenting me with a login screen, the session just restarted on its own. That fixed itself somehow.
And my system tray icons had shrunk in size, but the advice given previously in this thread got those fixed up quickly.