The not-so-mythical Halo 3 Title Update 2 is coming September 23, confirms Bungie. The update will be automatically downloaded, although some people may need to reset their Xbox 360's cache. Updates will include a new ranking system, some "invasive" changes to the playlists, new achievements and a visual overhaul to Bungie.net, which is slowly being rolled out now with more to come next Wednesday.
As for the achievements, which haven't yet been explained (we're willing to bet "Poor Yorick" has something to do with skulls ...), Smith notes that one achievement will be withheld until September 25, which happens to be Halo 3's birthday.