Wow, thanks for all the interest in my earlier response guys. In the above post I mentioned that, "Pretty sure that Jason dies early and Lucia is the actual protag." and I've even got a PM asking why I thought that. First let me say I don't have any insider info and this is just a hunch(based on intuition and not facts). It isn't anything that I know to be true. However, I think it has such a shock to hearing it that it would make a really good storyline. I'll give out my reasoning as to why I think this here but also realize that I could be completely wrong. I'm just one man who has seen the marketing material.
So let's start off by saying that Rockstar has a lot of pressure on them for this game to be good. Not just good but they want to put out the greatest game of all time. I really think that. They have been working on this for a long time. So with that in mind I have little doubt there will be some aspects of the story that are controversial and also that stick with us long after the story is over. I think the most obvious way to accomplish this is to kill off a beloved character and challenge expectations. However, this is not the only reason I think this. Jason is naïve while Lucia is fearful. He is a risk taker while she really only cares about keeping the people she loves safe. Jason is a young man who thinks he is immortal. This is starting to sound like a familiar story to me. The next thing to keep in mind here is gender. This game has shared protags but from everything I've seen the main character is Lucia. Jason is also a protag but really isn't as popular and isn't meant to be as popular. If Rockstar wanted to sell this game on dual protags I do not think they would choose Jason. Lucia is interesting, Jason is only interesting because of Lucia.
The most important reason is because of how good of a story this would be if it does happen. It would be difficult for Rockstar to pass it up. I foresee the beginning of the game playing out like this. Lucia and Jason are a street smart couple but Jason is a little naïve, he's a little too brave, and Lucia worries about him. The way he will die will be a double cross. Someone like who has spend time with both Lucia and Jason, perhaps even attended parties with them or at their home or perhaps who is Jason's boss. His death would be not at the beginning but at the end of act 1. The second act would become a revenge deal of sorts, think Kill Bill but with Lucia. I expect we may even get a Kill Bill reference in the game. Eventually we will get a raid on the compound containing the bad guy. Lucia will learn lessons from a wizened friend. People will assist Lucia on her quest and we will see some of the people that Jason beat up were also victims of the same man who killed Jason. These will become her compatriots on her quest for vengeance. There will likely be a jail break at some point where Lucia either is in jail herself(perhaps framed) and has to break out or is breaking someone else out.