gistfile1.js

$(function(){

	$("div#mw-content-text a").mouseover(function(){

		var new_link_title = "This needs to be changed.";

		$.get(this.href, function(data){
			var description_html = $(data).find('div#mw-content-text p')[0];
			new_link_title = $(description_html).text(); // this assignment doesn't work
		})

		this.title = new_link_title; // link title is undefined here

	});
})