[I've made a small updated fork][1], which is simpler. It adds **only the timeline** link. And it works today. And I will most likely maintain it (while I use any SEN site):

    // ==UserScript==
    // @name           StackExchange Timeline Links
    // @namespace      stackoverflow
    // @description    Add a timeline link to current question in the Stack Exchange Network
    // @include        http://meta.stackoverflow.com/*
    // @include        http://stackoverflow.com/*
    // @include        http://superuser.com/*
    // @include        http://serverfault.com/*
    // @include        http://*.stackexchange.com/*
    // @exclude        */reputation
    // ==/UserScript==
    
    (function(){
    	var start=function(){
    		$(".post-menu").each(function(){
    			id = $(this).find("a.short-link")[0].href.replace(/^.*\/a\//, "").replace(/\/\d+(?:#.*)?$/, "");
    			rlink = $("<span class='lsep'>|</span><a href='/posts/"+id+"/timeline'>timeline</a>");
    			$(this).append(rlink);
    			return false;
    		});
    	};
    
    	var script = document.createElement("script");
    	script.type = "text/javascript";
    	script.textContent = "(" + start + ")();";
    	document.body.appendChild(script);
    })();

  [1]: http://userscripts.org/scripts/show/102001