<?php
$currentlang = get_bloginfo('language');
if($currentlang=="en-US")
$link_text="All Products";
else
$link_text="Dummy Text";
?>
$return_string .= '<li class="wpc-category ' . $class . '"><a href="'. get_option('catalogue_page_url') .'">' . $link_text . '</a></li>';