Figured it out:
– Create a blog specifically for WoW achievements.
– Install http://feedwordpress.radgeek.com/, and then find my character feed using the WoWArmory.
– Set the Syndication to syndicate that character feed.
– Feed shows up Activity via blog posts from the blog I created for WoW achievements.
It works in the sense that it changes the avatar links, but it also leaves the name links as they are and tries to send all activity “view” links to /author/name/* instead of where they actually are – /members/name/*.