YUI 3.0.0 beta 1 is now available for download from YUILibrary.com.
From the Yahoo! User Interface Blog:
"This release takes YUI 3 out of its preview phase and brings its APIs to a near-final state. For those intending to implement YUI 3, the 3.0.0 beta 1 release is a good place to begin the transition. If you’ve been working with the latest preview release, George Puckett has provided a comprehensive 3.0.0 beta 1 changelog to guide you. We look forward to hearing your feedback as you begin working with 3.0.0 beta 1, and we’ll work hard to address that feedback as we prepare for a GA release in the coming months."
Some very interesting things made this release
"StyleSheet: StyleSheet makes it easy to create and modify CSS rules on the fly, allowing you to dynamically style page elements with fewer repaints."
Add stylesheets dynamically!
"ImageLoader: ImageLoader allows you to defer the loading of images that aren’t in the viewport when the page paints, throttling bandwidth usage and improving performance"
Images won't load until they enter the viewport, for longer pages, or hidden elements this is pretty huge. The bandwidth savings could be worth it.