the "nvidia" driver is currently broken in Natty, see Bug #711409
you should be able to boot in "recovery mode" and rename file "/etc/X11/xorg.conf" (e.g. "/etc/X11/xorg.conf_backup")
this should allow to boot the system using the fallback "nouveau" video driver, at least thats how it worked for me.
we have to wait till bug #711409 is fixed.
@Doug
the "nvidia" driver is currently broken in Natty, see Bug #711409 xorg.conf" (e.g. "/etc/X11/ xorg.conf_ backup" )
you should be able to boot in "recovery mode" and rename file "/etc/X11/
this should allow to boot the system using the fallback "nouveau" video driver, at least thats how it worked for me.
we have to wait till bug #711409 is fixed.