It looks like the Mozilla Add-ons Blog was dropped from Planet. The last post I see on my feed is from May 31st.
Was this done intentionally? We use it to notify users and the community about problems with add-ons and plugins, so I think it's important to have it there.
See http://planet.mozilla.org/projects/, which is where all the 'projects' type blogs moved to. :)
Yeah, I just about to close this bug after learning about it. I wasn't aware it had happened already.