Seems unlikely that GTA4 will come out in Q1 of 2004. If that happens, it will probably be a choppy, poorly worked on game. I don't want Rockstar to rush anything, take your sweet time and produce a fantastic game.
Secondly, like pilgrimage said, how is that online dealy going to work? One person is the badguy and another plays the police officers? I'm not seeing great possiblities.