• Night of the Chompiis !!! - the first map of our new 4-player Co-op Survival mode, is now available! And includes a new Chompii mutation - the Spider-Chompii !
  
• Weekly Missions - the weekly mission system is now in place - new missions (to unlock character skins) each week! This week's skin - Obsidian Magmor! Note - check the status of your missions / collected skins via the new Collectibles section in the Unlocks screen.
  
• Dedicated Server enhancements - you can now see and participate in chat from the Dedicated Server console (useful for debugging, or letting folks that you're going to do server maintenance, etc.). We've also updated our Server Guide doc.
  

• Hallowe'en skin fixes! D'oh - we fixed a defect that caused folks to lose their hard-earned Hallowe'en skins - to compensate we've extended the Hallowe'en promotion (until Nov 12th) with minimal mission times (5 minutes / 15 minutes)
  
• Weapons tuning - we've tuned up the Slicer a bit (faster traverse) and Striker weapons (especially Harpoon mode - faster re-fire, less kickback, more lethal damage) to make them more competitive in combat - give 'em a try. The Riffer incendiary nail got a bit more fire aftertouch as well. More updates to come over the next week on these...
  
• Smaller updates! We've re-packaged things so that on average you'll have a lot less to download each time we update the game (which is important, 'cause we keep adding new features! )
  
• Achievement checks! MiBI now does extra checks to ensure that it keeps your Steam achievements and MiBI unlocks in sync with each other
  
• Special unlocks - info on the Slicer and Striker weapon unlocks have been added to the new Special unlocks section
  
• Voice chat controls - we fixed a defect where voicechat could get unmapped from the keyboard and/or 360 controller (especially troublesome since there was no way of adding it *back* to the 360 controller). You need to hit [Defaults] on the Controller config menu (just this once) if this issue has already affected you though
  
• No more duplicate servers - we are no longer showing servers twice if they're located on your local LAN
  

• New gameplay mode: Instant Action is now available to players who have completed the story campaign.
  

• Localization fixes for international release
  

• Fixed possible issues when launching the Left 4 Dead 2 Demo
  

• Added Bill's Hat for players who pre-purchase Left 4 Dead 2
  
• Fixed client-side perf problem after changing levels on Koth_Harvest_Event
  

• Various fixes related to Stats & Achievements
  
• Fix for missing "Paint Colors" on some Hidden-Cage puzzles
  
• Support for creating additional player profiles
  

More specific details on these changes:

• Player Profiles: SquareLogic now supports the creation of additional player profiles. Each profile has its own progress, stats, and achievements. However, additional profiles you create are (necessarily) non-Steam profiles, and therefore have a couple of limitations: (1) they store their savegame data locally on your hard drive, not online on Steam's Cloud service; (2) their stats and achievements are NOT uploaded to Steam (only your Steam player profile does that). You can delete and re-create local (non-Steam) player profiles as often as you wish; however, you may never delete your Steam player profile as that exists on Steam itself.
  
• Resetting Stats & Achievements: When you click the "Reset all progress" button on the campaign screen (above the "Achievements" button), you now get a confirmation dialog warning you that if you reset your overall progress, ALL of your stats and achievements will also be reset. If this is a Steam user, stats and achievements will also be reset on Steam. Note that resetting a specific region (like "Ocean") or location (like "Beginnings") will not reset any stats or achievements.
  
• Stat & Achievement Synchronization with Steam: Previously, stats & achievements earned while offline, or during the Demo, would not always properly get set on Steam. It turns out sometimes even when you're online that's the case, for reasons unknown (the Steam API reports the update but it never registers). So we've added code that attempts to re-synchronize your stats & achievements up to Steam whenever it detects they are out of date. The net result is that Steam should usually be up-to-date immediately but occasionally will miss a beat and get updated shortly thereafter (when you solve a puzzle or restart SquareLogic, etc).
  
• Regional Achievements: Achievements for finishing regions (Held My Breath, Cave Potato, Tree Hugger, Llama Mama, Clear Skies, Billions and Billions) and other similar Achievements (Clean Plate Club, Piece of Cake) will now only be awarded when you *actually* earn them. Any of these that you have already earned will now be correctly awarded to you. NOTE: Due to a variety of reasons, we have decided NOT to take away any achievements that have already been awarded to you prior to the patch. Note also that for Clean Plate Club and Piece of Cake you are not penalized for skipping any of the 12 "practice" puzzles prior to the Challenge Puzzle.
  

• Fixed bug that caused dedicated servers to become unjoinable over time without a restart or heartbeat update
  
• Fixed exploit that allowed players to end a campaign and return to the lobby without a vote
  
• Public players are no longer matched to lobbies that are idle for a prolonged period of time. These lobbies become "Friends-only" lobbies
  
• LAN servers list will now show listen server single player games as not joinable and will show game type as "single player" too
  

• Improve the steam service update process
  
• Fix a case which could cause a decryption failure for newly released games
  
• Fixes a crash when the Left 4 Dead 2 Demo starts
  
• Fix a rare crash on receiving a chat message from a user you don't know as a direct friend