Update, March 9: Just to put the implication of his words beyond any doubt, Newell says "Artifact is the first of several games that are going to be coming from us." We know three of these titles will be in VR.
Half-Life 3 is not confirmed, but feel free to add "Half-Life 3 confirmed" in the comments below.
Newell also explained why Valve have been focused on hardware and tech over the past several years. It all stems from concern that companies like Microsoft and Facebook had been hoping to emulate "the kind of closed, high margin ecosystem that Apple's done," whether with Windows, phones, or VR. "That started to really worry us, because we thought that the strength of the PC is about its openness... so we started to make some investments to offset that."
Those investments have ensured that we have at least one open platform for VR in the HTC Vive, but have also bolstered Valve's hardware design expertise.
"Now there's pretty much no project in the hardware space that we wouldn't be comfortable taking on," Newell says. "We've always been a little bit jealous of companies like Nintendo. When Miyamoto is sitting down and thinking about the next version of Zelda or Mario, he's thinking what is the controller going to look like, what sort of graphics and other capabilities. He can introduce new capabilities like motion input because he controls both of those things... That is something we've been jealous of, and that's something that you'll see us taking advantage of subsequently."
Original story, March 9: At today’s reveal event for Artifact, Valve made clear their plans to start releasing games again, after years of focusing on the Steam platform and new hardware endeavors. Succinctly, a presentation presided by Gabe Newell said “now we’re going to start shipping games again.”
Newell says they’ve done plenty of work in making other people’s game’s successful, calling out PlayerUnknown’s Battlegrounds - now by far the most popular game on Steam - as a particular example. Valve’s efforts in building the Steam platform and new bits of hardware have been a “bunch of work,” but that work hasn’t resulted in new games.
Valve will continue working on hardware, but this will go “hand-in-hand with software design.” That seems to mean that Artifact's 2018 release date just marks the start of new game launches from Valve, who haven’t published a standalone title since Dota 2 in 2013, aside from the VR collection The Lab.