It has begun! Valve allows enough time before the update is released. However, they grant us a glance at what we may expect on Thursday (probably) together with the Meet the Pyro Trailer. Today, they introduce the new map Doomsday in their recent  Blogpost.

Doomsday appears to be a map with a completely new game mode. No one knows anything specific or how it will be played. To follow the description, it may be a  "Capture the Files"-ish game mode, where a  nuclear case must be transported to a rocket and fill a tank. Well, at least that's the way I would interpret it. As usual, hell is breaking lose on the  SPUF-Forum, where you can read lots of other interpretations as well, e.g. in  this thread. Plus, with the new map new achievements will come, too. Unfortunately there are no facts about their content.

Those clicking on the blog by the tiny monkey 'Poppy Joe',  is forwarded to an old Valve-Comic-Page, that contains some minor funny articles and moreover the story of the 'Monkeynaut' Poppy Joe.

By and large, this is just a small "Sneak Peak". Therefore one can't say too much about the things mentioned above. Nonetheless, we are looking forward to test the Meet the Pyro Update (with official Counter) and  we keep looking for more solved riddles!

EDIT: If you click on the banana below the Counter, you are forwarded to  'Poppy Joe Files'. These files explain what happened to the rest of the Monkeynauts! Thanks to AgentBull for the hint!