Across the latest months, there has been a noticeable development effort on quality in Ubuntu, process that covers numerous Ubuntu components, as well as daily ISOs.
As a consequence, users running development versions of Ubuntu (such as Raring Ringtail) are to immediately notice stability, usability and reliability (almost similar to a regular stable Ubuntu release).
Weeks ago, Canonical announced the birth of a new team of developers, team dedicated 100% to fixing Unity issues, without adding new features.
Ubuntu's Rick Spencer recently stated that Unity is to subjected to more tests, with the main purpose of improving and strengthening Unity.
Essentially, it seems that, starting with Raring Ringtail, Unity is to receive (process already started) much more (as compared to Ubuntu 12.10) development energy aimed at stability.
Ubuntu's Didier Roche has just announced that "starting from today [January 11th 2013], we have releases everyday", releases "pushed automatically to raring,..., as soon as they have a change in trunk and that tests are passing (46 components as of today)".
Further details are to arrive in the next weeks, yet, it is clear that Unity stands now on a more solid ground, being heavily tested.