Oh, never mind my last post... I just checked ccsm and found that (for whatever reason) the unity plugin was now switched off. With that turned on I do finally get the unity stuff back, and I could even log out and back in. Don't ask me why my last 50 attempts to do unity --reset (even blindly from the desktop itself) didn't solve the problem, but it appears to be fixed for now. Thanks a lot for all the helpful comments!
Oh, never mind my last post... I just checked ccsm and found that (for whatever reason) the unity plugin was now switched off. With that turned on I do finally get the unity stuff back, and I could even log out and back in. Don't ask me why my last 50 attempts to do unity --reset (even blindly from the desktop itself) didn't solve the problem, but it appears to be fixed for now. Thanks a lot for all the helpful comments!