Ever so often the video game business takes a step back, and stops taking itself too seriously. This has happened today, as a joke Half-Life 3 banner is adorning the front entrance to Gamescom 2016 in Cologne, Germany.
The banner is paid for by spieletipps.de and GIGA games, and actually says when you read the bottom line: "Half-Life: 3 editors who played it back then."
So as much as it would've been an awesome confirmation of the game, it's really not, but instead it's a rather excellent prank. Well done guys.