While EXTJS 3.0 is on the way with a roadmap setting deadlines for early 2009, Jquery continues its path on the way to serious lightweight alternative to the massive EXT : JX extension for Jquery includes the viewport paradigm on which relies every EXT JS application.
Web based interfaces
In spite of huge progress and impressive use of ease, Jquery is not there yet : for the development of applications many developers have chosen the exhaustivity of EXT JS. Have a look at google code hosted project in development : ecartcommerce, CMS jimw, both ext js and zend framework based. In the world of content management systems, mysource is making the news with a new video that demonstrates inline editing, and other exciting Rich Application features.