GUI unusable after upgrade from F 17 to F 19

[Joe Zeff]

First off, the upgrade didn't go that well, hanging (with no disk 
activity) at about 60%.  Ever since, the GUI has been unusable even 
after I cleaned up over 1,000 duplicate packages from the CLI.  There's 
a mouse pointer, but it doesn't move, and the keyboard is ignored.  All 
I can do is force a reboot with either the reset button or the Magic 
SysRq Key.  (No, that doesn't get me back the mouse/keyboard.)  Looking 
through /var/log/Xorg.0.log by ssh from my laptop, I find this:

[    41.590] (WW) Hotplugging is on, devices using drivers 'kbd', 
'mouse' or 'vmmouse' will be disabled.
[    41.590] (WW) Disabling Mouse0
[    41.590] (WW) Disabling Keyboard0

and checking through an old log, from before the "upgrade," I see no 
mention of Hotplugging.  Does anybody here know where to look and how to 
fix it without a fresh install, which is an option I won't even consider 
as yet because that's just giving up, and I'd rather learn from this.