With Day of Defeat: Source updated to include Steamworks supports, it seems to be Counter-Strike 1.6 that’s next in line to get the new features. If you’re a Counter-Strike 1.6 owner, you are now able to install a beta version of the game that includes Steam community integration.

Counter-Strike 1.6 Beta

Integrated Steam Community features into Counter-Strike

In-game player name now automatically uses player’s Steam Community name

Avatars are displayed on the scoreboard)

Other Fixes

Prevented some cvar exploits (thanks to AnAkIn for pointing them out)

To install the beta, run the command steam://install/150.