Wait, I refreshed the page a few times, and once, I got:
<html>
<head>
<title>MtGox.com</title>
<script type="text/javascript">
var AKSB=AKSB||{};AKSB.q=[];AKSB.mark=function(b,a){AKSB.q.push(["mark",b,a||(new Date).getTime()])};AKSB.measure=function(b,a,c){AKSB.q.push(["measure",b,a,c||(new Date).getTime()])};AKSB.done=function(b){AKSB.q.push(["done",b])};AKSB.mark("firstbyte",(new Date).getTime());
AKSB.prof={custid:"223233",ustr:"",originlat:0,clientrtt:19,ghostip:"23.51.248.44",ipv6:false,pct:10,xhrtest:false,clientip:"130.223.174.194"};
(function(b){var a=document.createElement("iframe");a.src="javascript:false";(a.frameElement||a).style.cssText="width: 0; height: 0; border: 0; display: none";var c=document.getElementsByTagName("script"),c=c[c.length-1];c.parentNode.insertBefore(a,c);a=a.contentWindow.document;a.open().write("<body onload=\"var js = document.createElement('script');js.id = 'aksb-ifr';js.src = '"+b+"';document.body.appendChild(js);\">");a.close()})(("https:"===document.location.protocol?"https:":"http:")+"//aksb-a.akamaihd.net/146060/aksb-a/aksb.min.js");
</script>
</head>
<body>
<p><img src="/img/mtgox_logo_mail.png"/></p>
<p>Dear MtGox Customers,</p>
<p>In light of recent news reports and the potential repercussions on MtGox's operations and the market, a decision was taken to close all transactions for the time being in order to protect the site and our users. We will be closely monitoring the situation and will react accordingly.</p>
<p>Best regards,<br/>
MtGox Team</p>
</body>
</html>
This is very odd behaviour.