It's worth pointing out that a lot of people will be coming who follow Heritage Action on Twitter and Facebook and that don't visit TMA, so a roll-call on TMA won't be by any means as comprehensive as it once was.
Due to past nastiness, it was decided that the Megameet wouldn't be formally announced on TMA any more, but rather on Heritage Action's own website via the Heritage Journal (http://www.heritageaction.org.uk) - as well as the aforementioned social media outlets.
Keep an eye on the Journal, as an announcement is due soon. You could always follow the account on Twitter for updates, which, among other things, announces all new blog posts, of which there are new ones every day. (https://twitter.com/#!/heritageaction).