The awaited FPS was cancelled but it is now coming back... Maybe.

Update: GSC reconfirmed the announcement with a tweet

Original article
GSC Game World 2007 post-apocalyptic open-world FPS S.T.A.L.K.E.R.: Shadow of Chernobyl was buggy and cut-down compared to what was promised but it was anyway an istant hit!

The series was so successful that spawned other two spin offs: a prequel called S.T.A.L.K.E.R.: Clear Sky (2008) and a pre-sequel S.T.A.L.K.E.R.: Call of Pripyat (2010) that connects the first two. The actual sequel was announced in 2010 and planned to be released in 2012 but it never saw the light of the day and was cancelled in 2011.

S.T.A.L.K.E.R. 2 cancellation was due to GSC Game World dissolution in the end of 2011, after the studio encountered financial problems (yet to be confirmed but the cause seems to be the expense for console development of this new game). Skipping forward to 2014, GSC Game World reformed after many of the original team reunited and till now the only game released was the RTS Cossack 3.

By surprise from yesterday GSC Game World's website is showing a link in the "In development" category, which brings to the S.T.A.L.K.E.R. 2 official webpage, showing a 2021 release date... That's it! This is what we actually know about the new S.T.A.L.K.E.R. game but it is really a great news for the fans of this FPS series.

Waiting till 2021 is a long time, if you like the S.T.A.L.K.E.R. franchise and you feel the need for it, I suggest you to try S.T.A.L.K.E.R.: Lost Alpha: a great and free GSC authorized S.T.A.L.K.E.R.: Shadow of Chernobyl standalone mod that tries to recreate and complete the original S.T.A.L.K.E.R. experience, as it was showed in the alpha footage prior to the game release and it also tries to create the definitive S.T.A.L.K.E.R. experience.