Half-Life dev Valve will be adding more achievements to The Orange Box and other games on Steam, it revealed in reply to a fan email (as odd as that sounds).
Team Fortress 2 will be the first to receive the in-game accolades - which work in pretty much the same ways as Xbox 360 Achievements - and other Valve games such as Day of Defeat: Source and Half-Life 2 will apparently follow.
"We're planning on adding achievements to all of our games you touched on in your mail," said Valve's Erik Johnson in the e-mail reply. "We're just now coming out of the post-shipping haze, so these should start showing up on Steam pretty quick here."
"We're also planning on adding a bunch more to TF2, starting with an achievement pack for the Medic in the next week or so."
It'd be pretty interesting to see the statistics behind Orange Box's achievements, as it might be one of the first examples outside of 360 of how the in-game unlockables cause fanatical game addiction. We won't play anything without them.