Alright, let's break down the trailer.
-Stealing a septic truck and spraying peds.
Kind of like a firetruck with the hose... which has been around since GTA3. But it's poo! It's DIFFERENT AND SICK!
This is one thing that IS actually different. Kind of out there to chuck a body 15 feet like that but whatever. It's a game.
-Dress up like a cop and rob a liquor store
-Streak in public
Ok, your character has no clothes and you run around? WOW that'll be entertaining for 5 - 10 minutes.
Fighting in a ring. Ok, not seeing the fun here. I can street fight anywhere, right? I guess you earn money that way?
-Run security for local celebs
That looked like a cutscene from a mission. Again, Vice City w/ Lovefist.
Every GTA since 3, but these guys actually made it part of the game.
-Trail blaze and demoliton derbys
Vice and SA again
Summed up, it's all the best parts of GTA ripped into one game with some unoriginal extras. Awesome, THQ. Awesome.