Am I the only one who thinks the voice in the trailer sounds Hispanic?.. I don't know why people think he's white.. but I guess the majority is probably right.
Packie - He left for the Airport at the End of The Baled of Gay Tony, so he'll probably be involved in the story.
The Old Guy - I don't think he'll be the Protagonist, because R* usually goes for the Rag 2 Riches Story, and it's a formula that has proved to work, No point changing it. Also he doesn't suit the young voice, I'd expect him to have more of a Italian or Irish American Accent.
GTA3 Protagonists - Just because R* says there'll be no returns, (..on several occasions.) I'm not falling for it. Is it really unimaginable that R* would lie? They would also missing out on a golden opportunity; people love returns.. hell, I even got a Semi when Ken Rosenberg came back for another game (..and I hated him in Vice City). I'm 50/50 that there'll be a return of a Protagonist.
Prediction: A Hispanic Guy coming from a shitty backround; got rich from his criminal past; met the right girl; retired for a Honest Life; started a Family and moved to a White Picket Fence Neighborhood; had it all taken from him; he's back to square one.. and has to go back to being a criminal. That's just a very basic idea.