jQuery 1.5 was released recently with plenty of bug fix and new effect. For those who wanted to make use of jQuery 1.5 in WordPress, here is how you can do it:

Open your functions.php file and copy and paste the following code.

if(!is_admin()){
wp_deregister_script('jquery');
wp_register_script('jquery', ("http://code.jquery.com/jquery-1.5.min.js"), false, '1.5');

Now, any theme/plugin that call the wp_enqueue_script('jquery') functions will return the path to the jQuery 1.5 script.