The next S.T.A.L.K.E.R game will have Strider from Call of Pripyat as the Player CharacterWith Strelok now having left the Zone his story has been pretty much wrapped up, but the ending monologue for COP implies that Strider and his fellow Ex monolith fighters still have a mission of their own, the next game will have you playing as Strider, exploring more of the ruined city to reveal Monoliths real purpose.
Aliens may be responsible for the Zone after allOk so the end of Shadow of Chernobyl tells us that C-Consciousness were the ones responsible for the anomalies and the 2nd incident, and that the alien interference is just a cover for this. But in Call of Pripyat there are a few hints that C-Consciousness may not have been in total control as was previously thought, for example:
The bandits at the factory/lab are blind due to the radiation in the areaSeriously, there has to be an explanation for why the ones there are noticeably stupider than every other NPC in the game.
The game takes place in the Half-Life universeThe SEVA Suit shares a voice with the HEV suit and "Gordon Freeman" appears. This Gordon appears to be older, and the Half Life PC should be in stasis in 2012, so I conclude that this "Gordon Freeman" is in-fact Gordon Freeman Senior. The Combine invasion will happen latter.
The guy who rescues Marked One at the start of So C will appear in Stalker 2.
The mercenaries have been hired to retrieve the data and material from the C-Consciousness's experiments into the noosphere.They spend most of Call of Pripyat watching the scientists or preparing for their expedition into the center of the Zone, and when they do mount the expedition, they really go all-out - without player intervention they'll even outnumber the surviving Monolith forces by the end of the game, and the mercs will effectively take over the city for themselves. Although there's a significant number of anomalies there, and the lack of looters means that there's still some useful stuff to be scavenged from the buildings, neither one of those things is really a good reason to mount a full-scale invasion. The data, on the other hand, might be just what their mysterious benefactor is looking for.
Nitro from Call of Pripyat actually is Vladimir Putin.STALKER takes place in an alternate timeline from our own, we already know. Nitro doesn't merely look like Putin, he actually is him due to different life choices he'd made in that universe. The Point Of Divergence between the STALKER universe and ours seems to be sometime after the 1986 disaster, when a group of scientists moved into the Zone in order to undertake dangerous experiments in psychic powers in secret. In our reality, Putin left the KGB to enter politics in 1991, plenty of time for his mind to be changed. In the game, Nitro is one of the few technicians who knows how to open the blackbox of a UAV, possibly hinting at a background in military intelligence. And frankly, they're visually identical to one another.