Nice timing. I have a couple of projects going that are extensively using the Yahoo User Interface Library, including some of the "beta components". I went to lookup some documentation on their site and found that they just released v2.3.0.
In one project we've been talking about using something like the JSAN loader to manage dependencies. The new YUILoader looks like a much better fit.
Also new and noteworthy: Base CSS (Vani was working on something like it; we love how Yahoo keeps doing the grunt-work here!), the Test Utility and the Rich Text Editor.
