Can't Boot to GUI After Update

I installed some updates today (18 Dec) and afterward I tried to start wow using wine and got a blank screen with the game cursor. I thought this was odd but decided a reboot would probably clear things up. Rather, things quickly went from bad to worse. The system won't boot now. It varies in exactly what I see on the screen but it will usually get to the ubuntu loading bar screen then cut to a lonely blinking cursor on a blank screen. At this point I can't type anything but I can access the virtual terminals and my wireless network connection is clearly working because I can use lynx to connect to google. Trying to startx from the terminal results in a screen of text, most of which flows by too quickly for me to read, but which contains a reference to an api mismatch.

Can anyone tell me what I should do here, or what information I need to retrieve to figure out what's wrong?