In context: For any newcomers to the PC gaming scene, you may not be aware that Valve made video games once upon a time -- and not just stuff like Artifact or Dota Auto Chess; which some feel are more trend-chasers than they are unique experiences. No, they made full-fledged games that often set new design standards in their respective genres, like Left 4 Dead, the Half-Life series, and even Team Fortress 2.
It's been quite a while since those games came out, though, and fans have been eager for something more substantial ever since. And, according to Tyler McVicker from the Valve News Network YouTube channel, said fans may just get their wish sooner rather than later: Valve is apparently working on an entirely new project based on the Source 2 engine.
While it's unlikely that this project will be anything with the number three in its title (everyone knows Valve can't count past two), references found in Dota 2 code via the Source 2 SDK following a major recent update reportedly reference a number of interesting gameplay mechanics.
The list includes stealth, a top-down tactical camera, NPC schedules of some kind, a minimap, and the term "Citadel" (which has referenced Half-Life in the past).
If you're wondering why a Dota 2 update would have anything to do with a new project, the answer is simple: nearly all of these features have absolutely nothing to do with Dota 2, and they were specifically found in a "low-level" engine update for the game. This seems to imply that this new project could share some source code with the long-running MOBA.
Perhaps it's a top-down stealth tactics game in the vein of Shadow Tactics or the upcoming Desperadoes 3, but set in the Half-life universe? Frankly, nobody knows for now. However, it's clear that Valve has something up its sleeve, and it's certainly not Dota 2 related.