levo - 5:55 pm on Jun 7, 2013 (gmt 0)
but there doesn't seem to be a way to mark key index pages for publishers
Just like events, you can markup every article on a index page. Don't forget to add itemprop=url for each and wrap all of them with schema.org/CollectionPage. Without a parent, Google+ picks the first item when you share/+1 the page.