Does Telltale have any interest in implementing some sort of achievement system for the PC/Mac games they sell directly?
Achievements have been implemented for both Xbox and PS3 versions of various TTG games, as well as the Steam version of Poker Night, so support for them certainly already exists in the Telltale Tool, and, as some of you may remember, the launcher has the ability to upload/sync information to the TTG website, which was used to unlock items for the ToMI Treasure Hunt. The achievements could be unlocked in the game, uploaded to the TTG website via the launcher when the game closes, and displayed/tracked in the player's profile.
Granted, I don't think it would be that easy. Telltale would have to implement their own achievement support, be it by an overlay, main menu item, or both. On top of that, I doubt TTG would want to revisit old games to update them. I'm sure updating the launchers wouldn't be much of a hassle, but tweaking the games themselves to enable achievements would be a pain, and most likely wouldn't provide enough of a return-on-investment to warrant the effort.