There will be tons of things to do in this game like online free roam, multiplayer and more. Here's some info on the game.

http://www.gamespot.com/pages/forums...ic_id=26266475


Something else that is pretty cool. Got this off wikipedia but it's confirmed.

"Following a partnership between Rockstar Games and Amazon.com, players will be able to purchase real world MP3s through GTA IV's in-game mobile phone. If the player hears a song they like on the radio, they will be able to 'mark' the song by dialling ZIT-555-0100 on Niko's phone. They will then receive a text message providing the name of the song and the artist. If the user is registered on Rockstar's 'Social Club' website, they will also receive a real world email with a link to an Amazon.com playlist where all of the player's marked songs will be listed and available to purchase.

Initially, this service will only be available in the US."



I'll list of the multiplayer modes as well.

* There are 15 multiplayer game modes in GTA IV. PSM had an opportunity to play 7 of them. The rules of each game are determined by the host.
* Multiplayer supports upto 16 players.
* Your online character is fully customizable. You can alter his race, sex, hair, clothing etc.
* The game modes featured are as follows:
Multiplayer Preview
Multiplayer Preview
PSM Spain has all the first details on GTA IV's multiplayer system.
1. Hangman's NOOSE
2. Car Jack City
3. Bomb da Base
4. Bomb da Base II
5. Mafia Work
6. Team Mafia Work
7. Deathmatch
8. Team Deathmatch
9. Turf War
10. Cops n Crooks
11. Race
12. GTA Race
13. Deal Breaker
14. Free Mode
15. (some other mode?)
* In Race and GTA Race, the host gets to decide which vehicles are involved, and the number of laps to be played. You can shoot and throw molotovs from the window, and even steal your rivals' car.
* In Deathmatch and Team Deathmatch, the host gets to decide whether the police can intervene or not. The host also gets to decide the number of pedestrians, the amount of traffic, and the type of weapons.
* In Cops n Crooks, one team play as cops and the other play as criminals. The cops must stop the criminals from escaping. They can monitor the locations of the criminals on their GPS systems, while the criminals have no idea where the cops are.
* In Mafia Work and Team Mafia Work, you play as one of Kenny Petrovic's mafia henchmen. You must complete hits ordered by the boss (via the cellphone) before your rivals are able to do so.
* A single-player mission called "Hangman's NOOSE" features co-op. You and your friends will be able to escort a mobster, while being pursused by a SWAT team.
* The map used in multiplayer is the same map that is used for single player.