jQuery 1.4.2 is out on February 19th, 2010. This is the second minor release on top of jQuery 1.4, fixing some outstanding bugs from the 1.4 release and landing some nice improvements. There were a total of 40 tickets closed in this minor release.
In this release we’ve added two new methods: .delegate() and .undelegate(). These methods serve as complements to the existing .live() and .die() methods in jQuery. They simplify the process of watching for specific events from a certain root within the document.