Metro: Last Light, the followup to 4A Games' stellar Metro: 2033, will not have a competitive multiplayer mode as the studio has dropped it. Multiplayer had been promised from the get-go, but now it's been removed so 4A can better focus on the game's single player. However, it seems the decision to drop multiplayer is to everyone's benefit, as 4A Games explains it thusly: "We never dedicated too many resources to the MP component beyond prototyping; it never entered full production. By making the decision when we did, we think the single player campaign will benefit as a result."
The developer says it was "probably a mistake" to announce the mulitplayer component so early on, but does not rule out the possibility of it being included as an add-on once the game arrives. The team doesn't want to throw away any work, even if it's just prototypes, so maybe we'll hear more on the multiplayer side later. Personally, the Metro games should be a single player story, possibly co-op, so I'm not too heartbroken over the lack of competitive multiplayer at launch. Metro: Last Light is expected to arrive sometime next year after it was delayed, and will launch on the PC, PS3, and 360.