Updates to Team Fortress 2, Day of Defeat: Source and Half-Life 2: Deathmatch have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:
Source Engine Changes (TF2, DoD:S, HL2:DM)

• Marked mem_force_flush as a cheat to prevent client exploits
• Fixed %n console crash in the client

Team Fortress 2

• Added new items:
  • The Red-Tape Recorder
  • The Huo Long Heatmaker
  • The Flying Guillotine
  • The Neon Annihilator
  • The Triad Trinket
  • The Champ Stamp
  • The Marxman
  • The Human Cannonball
• Added new promo items
• Fixed sappers attaching incorrectly to teleporters that are still building
• Improved reliability for finding a coach
• Fixed Engineer training shotgun and pistol images being swapped
• Fixed GetPlayerItems web APIs not respecting inventory privacy settings
• Quickplay beta: Fixed bug causing game servers to sometimes stop receiving traffic upon victory condition
• Quickplay beta: Added more status information while in the matchmaking queue