According to ITCChannel, 4A Games stated that there will be a PS4 version of Metro Last Light, and most interestingly, that it could come with the original game. It was also mentioned that 4A is considering implementing a DLC season pass since five separate pieces of content is planned for the game giving you the chance to experience the single player from the perspective of other characters. Finally, they mentioned that the game may see a multiplayer mode added as a separate release, possibly as an XBLA game.
Joystiq followed up and discovered that all these exciting developments are just ideas at this point in time and there is no official confirmation for any of these features. They specifically told Joystiq, “…All these ideas are just ideas at the moment. It will be some time before we can officially commit to any of these projects or suggest when they might materialize. They genuinely might all happen, but equally none of them might happen. Anyone expecting Metro: Last Light as a PS4 launch game is probably going to be disappointed.”