Official mockups expose an enhanced Unity greeter for Ubuntu 12.10
Although being an LTS, Ubuntu 12.04, along with security and stability "precise" enhancements, introduced a relatively "medium" amount of visual improvements, landed in various parts of Ubuntu.
Naturally, the new (at-the-moment development version) Ubuntu release, Quantal Quetzal, is to probably be considerably more opened towards new features, both in the adoption of the full no-compromise up-to-date GNOME stack (stack similar in landed apps as the previous Ubuntu releases) and bold visual improvements, bearing an awaited approach, where "completing" the concepts (implemented partially in Precise Pangolin) definitely plays a relevant role.
According to a launchpad blueprint, Unity greeter is to probably receive the "missing" bits, thus (at-the-moment at a mockup level) presenting a full-fledged login experience, where improper visual artifacts are to be removed.
A definitely exciting change is the confirmation dialog that, after the user types the password, exposes a black-ish transparent dialog with a running spinner, continuing its spin until the desktop is ready, consequently, removing various visual inconsistencies during the login process, and presenting a one-piece solid and fluid login experience.
The mini Dash (that houses the username, Ubuntu logo, etc) is to be further enhanced, featuring a separate back button and properly exposed text (when the situation requires it).
Another possible additions are transparent indicator menus, that are to borrow the panel's texture, probably a step towards consistency across the greeter.
The full official specifications are available on https://docs.google.com/a/canonical.com/document/d/1ypvxcSmwNKKMZawit-0r...