Paul Thurrott published an overview and screenshots of Windows Vista Build 5456

Though there are few major changes in build 5456, which, despite the naming convention used on its desktop, is part of the release candidate (RC) build tree, and not a direct successor to Beta 2. But we shouldn't expect major changes at this stage: After all, Windows Vista was mostly feature complete as far back as February 2006. But what we get in build 5456 is dramatic improvement in reliability, usability, performance, and fit and finish. It is, quite simply, the build Microsoft should have shipped as Beta 2 to millions of people around the world. This build is so much better than Beta 2, in fact, that I'm begging the company to offer it to everyone that signed up for the public beta through the Community Public Preview (CPP).

Windows Vista Build 5456 Overview and Screenshot Gallery