YUI 3.x :: YUI Library
A comprehensive list of what has changed in YUI3 as it goes to beta. The end result for me is that I have code that will break. :( But the nice thing is that the API, especially around Node is getting saner. NodeList no longer behaves like Node, for starters, but this means you have to be mindful of if you're dealing with a list or a Node, which before you didn't have to worry about. So no size() call on Node to determine this; an empty NodeList is [] rather than null; and so on.
