I'm guessing that Michael takes out Snoop. Right before the scene where he points the gun at someone in the truck, Chris is in a warehouse or something. So that kind of rules him out. The other reason for my guess is that Michael wants revenge for Snoop pushing him in the chest and telling him to shut up about what Marlo should or shouldn't do. A little disrespectful and humiliating, no? Even though Chris was the only witness, no one wants to get punked like that. Unless of course they are a punk, which Michael is not.

And third, doesn't Snoop usually drive? Chris drives Marlo, but when it's Snoop and Chris in the car Snoop is the driver. But then Michael seems to be on the driver side of the car when he points the gun. He's more junior to Snoop, so I guess he'd be driving if it was just him and Snooptizzle in the truck. I'm rambling, but there are lots of permutations here. One thing's for sure: no weak-a$$ Soprano-style ending.