According to the latest "ubuntu-meta" package update from the Ubuntu Quantal Quetzal repositories, Unity 2D will no longer be installed by default in Ubuntu 12.10, and Unity 2D users are being transitioned to the Unity 3D session, just like it was discussed at UDS-Q.
Further more, the latest Unity package, uploaded to the Ubuntu Quantal repositories a few hours ago, uses a "dummy" Unity-2D package, so Unity 2D is no longer available in the repositories and won't be installable at all in Quantal.
Ubuntu users without graphical acceleration will be able to use Unity 3D thanks to llvmpipe, so there will be no fallback session anymore and Unity will look the same for all users.
