It hung for several hours but came up when I hit CAD. Files appear to all be there. Tab Mix Plus on firefox is deader than last weeks hamburger, but I can live with that I guess. The firefox icon on the main task bar has been replaced with the international "no" symbol (red circle bisected with descending slash) which I also find somewhat unusual. The dialog manipulation controls are now on the upper left corner instead of the right. I seem to recall that that was a configurable feature; something I will look into tomorrow. mplayer movie player is gone. pity.
For the moment, it doesn't look like it screwed up too bad. Bed time now, I think. Tomorrow is a new disaster...
Thanks all.