Computerbild-Speile,a German Video Gaming magazine played the same demo that many online gaming websites did. IN their latest issue on sale now they list a few interesting features we have not heard much about yet.

• Pedestrian reactions to your driving, actions and interactions with them are more realistic than in previous GTA's.
• The wasted system we all know and love is still intact. If you die, you end up at the nearest hospital and loose your weapons as well as a small amout of cash. What is new here however is that instead of appearing at the hospital several hours later you now end up at the hospital the new morning.
• One button press will get you into a car, a second then allows you to start the car, most likely hot wiring the car works the same way.
• Niko wears a helmet while riding motorcycles, unknown is if he is required to wear it or if you can ride with or without it.
• Surroundings are more interactive, bullet holes from direct gunfire and environment reacting to explosions for example will all have an affect on the surroundings.
• You can find “useful things” in cars that you hijack. It's unknown as to what as of yet, but most likely weapons, money, items and special extras that help you through the game will be discoverable.

Thanks to RockstarUncut for the information!