Calling it now. Years from now, we're going to be playing the final, polished version of this mission. And we're going to immediately hit the Leonardo DiCaprio pointing meme.
Sidenote: I feel like R* will make the main story able to be completed entirely through online co-op. They might blur the lines between GTA online, and the single player a bit.
Imagine pulling off a main story heist, using online co-op, in 2 completely different locations, at the same damn time. And each heist have it's own set of choices, and problems. That will affect the outcome of the other player's story, as well as your own.