Here is the most important bits of news, straight from Game Informer:

Your character is a former street soldier for the Forelli Brothers, known as Tommy Vercetti.

In this game, you can snipe the tiers of cars and they pop, making vehicles go slower.

Martial arts play a large role. allowing you to kick backwards and forwards!

The character wears blue jeans, a blue hawaiian shirt, and has short black hair. He looks a bit older then the GTA3 guy.

Fully modeled interiors of a lot of buildings!!

Much easier and more efficent targeting system..

Possible SWAT Missions, but R* isn't saying for sure.

MUCH Better Graphics!

Many vehicles are inspired by 1980s sports cars

There ARE motercycles and helecoptors, both that you can use easily (unlike the dodo ><)

Duel Crosshairs make aiming as easy as 1-2-3!

40 different weapons, including the 15 from GT3. Tommy will be able to use a MACHETE!!!!!!!

You can crouch behind things in the midst of battle!

In certain missions, you can deliver pizza

All of Miami is unlocked from the start