everybody just up and decided Episode 3 must have been turned into Half-Life 3 because it was taking so long
when in reality, it was probably just shelved for L4D and Portal 2...and then everything along those lines got shelved for DOTA and their continued experiments with CS:GO and TF2
the HL3 thing never made sense to me, because Valve had done the episodes originally because they wanted to follow up HL2's world/plot but not make a whole new game and had often said a new game would be when they had something big and new enough to justify a 3...they arguably had done the same thing with the first game but farmed out the work on the expansion packs to Gearbox, it was still Valve's story rather than brand new content
i think until Valve can find a new way to do single-player where there's continuous content yet it remains single player, we won't see one from them, especially when everything else is being so profitable for them and it seems like the company in general enjoys working on it, so guys like Laidlaw, etc. left...I think Arkane Studios also picked up some of those story/scenario-driven Valve people too? some of those THQ salvage operations too i think?
if we see a 3 franchise from Valve, I'm going to just assume it's L4D3...they're porting CS:GO to Source 2, TF2 is probably in a codebase and content situation where they can't easily port it and it's an ideal entry point F2P game anyhow so leaving it for lower end spec works out like CS and CS:S did for a decade...and there were those leaked slides, so L4D3 with something like multiple characters to choose from with minor stat differences but still making up your foursome? that would fit the hero shooter stuff into it though maybe you don't need to do that since it's been EIGHT YEARS since 2 and just putting out a bunch of new Source 2 quality content could be enough plus it in VR obviously
for some odd reason i get the impression that Valve may have wanted Portal 2 to be a very different long term thing, they never really backed it up post release like they were suggesting even when Gabe wandered out at the Sony conference there was confusion about what exactly it would mean for the console side...then DOTA and Icefrog swept in there suddenly and sorta took over the company not long thereafter...arguably other games have made more out of the Workshop setup than Valve has, hell, even a huge title like Black Ops III uses it for its restoration of all the old mods
i do think we'll see a bit more from Valve soon though, beyond that card game, they pushed DOTA 2 onto Source 2 first, CS:GO is supposed to be onto it very soon and that's not an entirely internal Valve product in the first place, DOTA 2 seems like it's finally in a position where it's "official" and it's not a game that pushes VR which is Gabe's other obsession, while L4D seems like a perfect series for that
then again, maybe this is a stealth announcement of HL3, they wrapped up 2 like Xenogears wraps up its ending minus the cutscenes, and 3 will be some new crazy thing they announce soon...that's just a basic game framework the length of two Lost Coast's but with all the new fancy Source 2 tools and at the end says "modders go to it making hundreds of hours of content with our new tools, e-mail me at gaben@valvesoftware.com" and they "build" the game that way