So I've been observing the Drupal 7 UE redesign project and have made another tremendous discovery. There is little (probably nothing) new under the sun. So when you want to hit the 80% principle, just copy from others.
So you have some of the intial Mark Bolton concepts & Lullabot's Buzzr UI for Drupal. Then you look at other CMS's, specifically Concrete5 and CMS Box (one of 2008's best UIs according to Jakob Nielsen). And you come to the conclusion that a CMS requires, drum roll please, a header, overlay window and inline editing -- three things that are in each of these CMSs and CMS designs.
This begs the question just how much original usability testing, getting to know your user time is really required. Couldn't you just copy what has gone before you? Or perhaps it is really good validation that the basic concepts are right on.
And a final thought. These concepts really aren't going to make Drupal unique... something else is required.Hopefully Bolton's concept of a "Tool for Site and Page Structuring" can be that unique element.