The Internet Rumour Mill™ is once again churning, with a new screenshot spotted in the wild of what appears to be a Source Engine 2 PowerPoint presentation.
Revealed on NeoGAF
by the supposedly reliable "crazy buttocks on a train" leaker (who previously leaked a number of PS4 and Xbox One information), the screenshot not only features the new engine in question, but also demonstrates the graphical prowess with the Plantation level from Left 4 Dead 2 rebuilt in the new tech.
As with any rumour found on the Internet, you should take this one with a grain of salt. Previous evidence has surfaced suggesting that Valve may just be looking into a new engine, though it is hard to tell just when we may see any official announcement on the subject. Maybe one day we will finally get to see Ravenholme again. Check out the screenshots in detail over here