Cannot map array to observableArray using ko.mapping Options

http://groups.google.com/group/knockoutjs/browse_thread/thread/b8a63ce2265ac5cb#

HTML

<script src="http://cloud.github.com/downloads/SteveSanderson/knockout/knockout-2.1.0.js"></script>
<script src="https://raw.github.com/SteveSanderson/knockout.mapping/master/build/output/knockout.mapping-latest.js"></script>
<script src="http://cloud.github.com/downloads/SteveSanderson/knockout/jquery.tmpl.js"></script>
     <ul data-bind="foreach: model">
         
        <!-- ko if: $index() % 2 === 0 -->
        <li>            
        <!-- /ko -->    
            
        <span><a data-bind="attr:{href: $data.url}, text: $data.title"></a></span>
            
        <!-- ko if: $index() % 2 !== 0 -->
        </li>
        <!-- /ko -->
       
    </ul>

JavaScript

var data =  [ {"title":"first link", "url":"http://site.com"}, { "title":"second link", "url":"http://site2.com" },{"title":"third link", "url":"http://site.com"}, { "title":"fourth link", "url":"http://site2.com" }];

var model= ko.mapping.fromJS(data);

$(function() {
    ko.applyBindings(model);    
});