About The Release (from the jQuery announcement)
This release saw 83 fixed bugs and a total of 460 closed tickets. The test suite (which now has 4437 tests) passes in all the browsers that jQuery supports - and more. We verified the suite passing all of the following browsers:

* Safari 5.0.3 / 4.0.5 / 3.2.3 / 3.1.2
* Opera 11.01 / 11 / 10.63 / 10.54 / 10.10 / 9.64
* IE 6 / 7 / 8
* Firefox 4.0b9 / 3.6.13 / 3.5.11 / 3.0.19 / 2.0.0.20
* Chrome 8.0.552.215 / 8.0.552.237 / 9.0.597.67 Beta / 10.0.642.2 Dev

Additionally all of the API documentation for the release can be found on the API site: jQuery 1.5 API Documentation.

A full schedule of our upcoming releases can be found on our roadmap. Right now we’re planning on doing major jQuery releases more frequently (likely a couple times a year, rather than once per year). So, without further ado, what’s changed in jQuery 1.5?