The Launchpad bug where boot is stuck in Plymouth, gdm greeter not showing

Just helping Google here: apparently the issue of GDM not giving a login screen after Plymouth has finished is Bug #441653: xf86OpenConsole: VT_WAITACTIVE failed: Interrupted system call. For me this issue popped up after upgrading an NVidia-driven machine to Lucid and thus switching to Nouvaeu, though I can’t be sure it wasn’t there even back in Karmic.