The forum post in question
Important notes from the translationsGamespy wrote: On the site GTA Forums, user nevermikel has posted several pages of GTA4 scans from the most recent PSM Spain, as well as translations. According to the post, there will be 15 multiplayer modes in GTA4 supporting up to 16 players at once. Rules will be set for each mode by the host, and you will be able to customize your character's appearance, including "race, sex, hair, clothing etc."
The game mode list includes Hangman's Noose, Car Jack City, Bomb da Base and Bomb da Base II, Mafia Work, Team Mafia Work, Deathmatch, Team Deathmatch, Turf War, Cops N Crooks, Race, GTA Race, Deal Breaker, Free Mode, and an unknown mode. Cops N Crooks sounds like the best of the lot, where one team gets high-tech police gear and an imperative to catch the crooks, and the other team gets to be criminals. We presume that includes getting rockets.
We're still waiting for comment from Rockstar.
The Multiplayer takes place in the exact same city as the Singleplayer, 16 player max, 15 multiplayer modes, some sound like re-treds but there looks to be a solid nine modes in that 15 mode list.
The PC port of this game can't be close enough I say.