A friend of mine introduced me to GWT. Google Web Toolkit.
According to Google "Google Web Toolkit (GWT) is a development toolkit for building and optimizing complex browser-based applications. Its goal is to enable productive development of high-performance web applications without the developer having to be an expert in browser quirks, XMLHttpRequest, and JavaScript."
Its been around for a few years now - since 2006 version 1 release, and gaining traction. I spend about 3 four hours since last night looking at it and really like what I saw. Specially given the issues currently my client is facing on writing a Web 2.0 app.
From what little I could figure out.. programmers write AJAX apps using Java, and when that app is deployed, the GWT cross-compiler translates the Java Application to a set of JS files that are very much optimized. Write in java - run as javascript? nice!
For those who are interested, a comparison of the different JavaScript frameworks is available here