Project participant Rey Bango points out on the blog Ajaxian today, "considering the churn rate for open source projects, [jQuery's 3rd birthday] is a monumental achievement."
If you're a developer and you haven't tried out jQuery yet - you probably should. As Jennifer Stuart wrote when she finally did this Spring, "Why I didn't jump on this bandwagon sooner, I'm not sure, but I am kicking myself for it."
With the addition of the jQuery code to the nonprofit Software Freedom Conservancy, companies using the code are far more free from fear of lawsuits for using it. For details on that development and a number of new technical additions to jQuery, see the announcement on the jQuery blog.