@gian-ava
adding the attribute could be done by jQuery but would be so much easier doing it in core, so should really be a trac request.
as for adding the scripts to the footer, I’m sure you can add ‘true’ to the end of the end of wp_enqueue_script like
wp_enqueue_script( 'tipsy-js', TEMPLATEPATH . '/js/jquery.tipsy.js', array( 'jquery' ), true );
