I'm sure it will have the usual, godmode, infinite ammo, infinite cash, all weapons, et cetera. But mabye in the future trainers will have the unusual options like stop time, lock wanted level, give pedestrians weapons, cars fly, etc will come if you just wait it out.
Godmode, infinite ammo, infinite cash and all weapons is enough. Please do it
Another problem is that it use GFWL to save the game if we're not online we can't save at all (trainers don't work when using GFWL) I guess we're screwed if there's no way to save without being connected to Game for Windows Live.
Well not entirely true as GFWL lets you create an OFFline account and save games that way. Dont expect to play online with an offline account though!
I just discovered there was a way to have offline account, it will help my cousin, he lives in a no Internet zone (altough they have High Speed Internet at the nearest city its not going to get where he lives at all, stupid rules of the small town where he lives prevent cable or any visible things from disturbing the view)