I'm a going to play and most likely enjoy the game, but i have a strong feeling i know at least one of the major plot points.
Basically i think Vergil will recruit Dante for his cause(to achieve more power for himself). Dante will learn something important, and start to question his allegiance with Vergil. That scene where Kat is shot in the trailer, i think it will actually be Vergil that shoots her from a distance. Then try to use that to control Dante and focus his hatred on the Demons/Mandus. Then Dante will eventually find out, they fight. If you payed attention to all the trailers, it wasn't hard to come to that conclusion.
The game's short. Someone will try playing on the easiest difficulty for an easy game for the sake of spoiling the story to the internet. Most likely /v/ would be the fastest to get info on since they'll most likely pirate or post the story really quickly. The antis here wouldn't give a **** buying it day one anyway, and I doubt the pros will try to speedrun it.