[Plugin: WordPress SEO by Yoast] breadcrumb microdata

If you want a breadcrumb with microdata
Please read this http://pastie.org/5052580

And change this line 255 – file class-breadcrumbs.php

$output .= apply_filters( 'wpseo_breadcrumb_single_link', $link_output, $link );

to

$output .= apply_filters( 'wpseo_breadcrumb_single_link', $link_output, $link, $i, $links );

Cheers

http://wordpress.org/extend/plugins/wordpress-seo/