Theory

[Zedo Mann]

Anybody who used the Steam UI back when it first came out in beta, may remember that brief time when we saw Achievements on Half-Life 2 (http://forums.steampowered.com/forums/showthread.php?t=1159053). I think I also remember seeing achievements (or reading about someone who saw) on Ep1 and CSS.
(Okay, I was wrong, people only wanted CSS Achievements, they were on Ep1 and Opposing Force (http://forums.steampowered.com/forums/showpost.php?p=13672341&postcount=20))

CSS suddenly gets updated with Achievements. Does this mean that HL2, Ep1, and Opposing Force will get Achievements soon too? :D

[Tes4o]

I seriously hope so. I recall that the 360 version of the Orange Box had achievements for every game.

[pengu1NZ]

I seriously hope so. I recall that the 360 version of the Orange Box had achievements for every game.

that's because xbox players love to show off their achievements like it's their career.