Those of you who've followed the series will likely know both Metro 2033 and Last Light are spin-offs of the original collection of books—the third and final entry of which released last year, and whose English language version is due December 10. The book's site offers a timeline covering both novels and games, where the last heading, marked 2017 and headed 'The next Metro video game', reads:
"It all adds up to something. Where the books end their story, the game will pick it up. An era of great discoveries lies ahead…The next Metro video game."
http://www.pcgamer.com/metro-2035-relea ... next-year/