Update: Destructoid has retracted part of its earlier news post as they say "we did receive a few phone calls". The website also claims to have access to the game's Xbox 360 achievement list, which they claim will remain a secret until Rockstar wants it to go public. This all but proves the authenticity of the retracted information below, so look forward to playing Cops 'n Crooks this April 29!

Gaming blog Destructoid is first on the scene with what it purports to be authentic details about Grand Theft Auto IV's mysterious (albeit confirmed) multiplayer modes. Straight from their "credible" source:

GTA IV will contain a deep multiplayer mode, including deathmatch, team play ("Cops 'n Crooks"), and some sort of ranked cooperative missions. Our source specifically talks about modes called "Deal Breaker," "Bomb da Base," and something called "Hangman's Noose," but gives no further details. The game will also feature ranked multiplayer races, likely across the game's open roads of Liberty City.
-- Destructoid.com, February 8th 2008

Source: Destructoid