That's right, Liberty City Stories will be the first console GTA game to properly feature a multiplayer mode.
The game will support up to six players at any one time, each game takes place on one of the islands. There will be seven game modes, two of which, 1UP got to play with.
Liberty City Survivor (you'll remember the GTA3 radio ad) is basically a Deathmatch. It can be played solo or team, and obviously the player/team with the most kills (or frags if you're an FPS gamer) is the winner.
Another game mode is Get Stretched, this is a version of Capture the Flag, except you'll be stealing the other teams' limousine!
They both contain a multitude of power ups that you might expect from a multiplayer game. These include mega damage, bullet-proof, radar invisibility etc.
We can assume from the article that these multiplayer modes will only be playable in Ad-hoc mode (with people nearby). It's not actually confirmed though so hopefully Rockstar will explain more at some point.
See 1UP.com's Multiplayer Preview for the full story.
And the 7 screens and 2 new artworks