I don't know what else is contained in your #wiki_article_list, but since you appended the <li> just right before this should work:
$(this).children('li:last').children('a').attr('href')
I don't know what else is contained in your #wiki_article_list, but since you appended the <li> just right before this should work:
$(this).children('li:last').children('a').attr('href')