Yes you can add links to the top menu items that can be used when JavaScript is disabled:
<a class="top-heading" href="http://www.g.co" onclick="return false;">Link</a>
So when JavaScript is disabled, the onclick will not run the script "return false;" then the default nav to www.g.co will be executed.
When JS is enabled, the onclick "return false" will be executed and cancel the navigation of the link.