Grand Theft Auto V's recently unleashed trailer triggered a tidal wave of rudderless speculation, chief among them being the potential reappearance of Vice City's Tommy Vercetti. Despite the trailer's narrator possessing a similar voice, it's been confirmed that Vercetti actor Ray Liotta did not contribute.
This does not mean that the man in the trailer couldn't be Vercetti, but considering Grand Theft Auto IV was a reboot for the universe, I wouldn't bank on seeing any familiar faces. GTA IV remade Liberty City entirely, from the locations to the people, and GTA V would likely do the same for Los Santos.
Still, now is the time for all kinds of hairbrained theories and arguments, so feel free to have at 'em!