Comment 14 for bug 1228567

@Colin: I'm experiencing the same issue. Installing updates to 14.04LTS on my laptop in early December has made the GUI on my computer unusable as well. It's a ThinkPad, I think with a stock Intel video chipset in it. Here is the output of my .xsession-errors file:

Script for auto started at run_im.
Script for default started at run_im.
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd main process ended, respawning
init: at-spi2-registryd respawning too fast, stopped
init: gnome-session (Unity) main process (11515) terminated with status 1
init: logrotate main process (11404) killed by TERM signal
init: update-notifier-crash (/var/crash/_usr_bin_nm-applet.104.crash) main process (11451) killed by TERM signal
init: indicator-bluetooth main process (11638) killed by TERM signal
init: indicator-power main process (11640) killed by TERM signal
init: indicator-datetime main process (11641) killed by TERM signal
init: indicator-session main process (11655) killed by TERM signal
init: indicator-application main process (11671) killed by TERM signal
init: Disconnected from notified D-Bus bus