Speculation was growing thick and fast that former 1980's protagonist Vercetti would be returning in GTA V, but Liotta's lack of involvement has taken the wind out of its sails.
The narration in the trailer talks about 'leaving their past behind' and settling down to raise a family, but things don't quite pan out as they wanted it. No protagonist is made clear.
It's believed that GTA V will star multiple main characters for the player to fill the shoes off, as Rockstar did eventually with GTA IV when they released Episodes from Liberty City. Each of the characters main stories intersected and the current thinking is that Rockstar will be going for a repeat performance.
A character in the new trailer did fit an 'older Tommy Vercetti'. Will he be returning but Rockstar just decided to recast the role? No release date or platforms have been announced for Grand Theft Auto V. The only confirmed facts right now are its modern day setting in Los Santos (Los Angeles) set in the fictional San Andreas state.