I have resolved my issue, or at least the aftermath of whatever the real issue was.
After talking to someone who ran into a similar issue with fglrx in IRC (I use Nouveau), he suggested doing a unity --replace while logged into Unity with a terminal open. I did that, and got my wallpaper back at least. Then I had the idea of running unity --reset, and that finally brought back Unity 3D in full. I have logged out/logged back in, and also done a full reboot, and didn't have the problem occur again.
I can't recall tweaking any settings via, say, CCSM or anything prior to the upgrade however, so maybe the real problem was that some setting(s) got messed up between versions?
I have resolved my issue, or at least the aftermath of whatever the real issue was.
After talking to someone who ran into a similar issue with fglrx in IRC (I use Nouveau), he suggested doing a unity --replace while logged into Unity with a terminal open. I did that, and got my wallpaper back at least. Then I had the idea of running unity --reset, and that finally brought back Unity 3D in full. I have logged out/logged back in, and also done a full reboot, and didn't have the problem occur again.
I can't recall tweaking any settings via, say, CCSM or anything prior to the upgrade however, so maybe the real problem was that some setting(s) got messed up between versions?