There's a rumor going around that Valve will be announcing a new game in the Half-Life series potentially on this coming Wednesday. This rumor comes from @Nibellion on Twitter. It's worth noting that @Nibellion also had a hand in leaking screenshots for the upcoming Resident Evil game, Project Resistance, before the game was announced, so there's a lot of potential of him being correct with this leak as well. However, it doesn't look like this will be a standard Half-Life game like the ones that have come before. It's rumored to be called Half-Life: Alyx, named after Alyx Vance from the previous games and it looks like it'll be a VR game.
No doubt Valve is trying to push their own VR headset, the 'Valve Index' but it's also interesting to note that Valve hinted at this happening way back in 2015. In an interview with Kotaku, Valve programmer, Jeep Barnett said, "We've said, 'Let's take some existing art and see how it fits,'" and later when on to say, "So yeah, we'll grab some headcrabs, we'll grab the machine guns from Half-Life, the rocket launcher—all those different fun things—and see how they play in VR. But right now, it's a tool for exploring the different kind of game designs we want to do."
The last time players saw a Half-Life game was in 2007 when Half-Life 2: Episode 2 was released. That game famously ended on a cliffhanger and fans have been biting Valve's ankles ever since begging for Half-Life 3. Valve has always been fairly quiet on the subject and in recent years, has seemed to shift their focus on selling games rather than making them. Just this year, however, Gabe Newell himself hinted at the possibility of a new Half-Life game's existence at the launch party for the 'Valve Index' by saying, “Milestones aren’t really the end of anything, they’re really the beginning. So Half-Life led to Half-Life 2, Source led to Source 2, the experiments that we did with Team Fortress 2 were what enabled us to build Dota… So, maybe someday the number two will lead us to that shiny integer glowing on a mountain someplace… we’ll just have to see.”
Here's to wishful thinking.