Very cool. We've been expecting this one since patch 3.0.2 came out (if it's in the game, why wouldn't it be in the Armory?) but obviously other priorities rose to the top before now. Blizzard did a great job with it, though -- they can all head off to the holiday weekend now without worrying about the update.
And then, when they get back, maybe we can haz an official API?
Update: Just noticed that Blizzard also has a news feed on the main page when you log in that tells you about goings on and realm firsts for your character specifically, from who's downed the heroics recently to the first characters to 80 on your own realm. I wonder what they'll report on when all the firsts have been taken, but we'll have to see -- that might be an interesting feed to follow (they provide RSS for it as well).