This is something I've started to think about. Before his death, Sollozzo wants a deal with the Corleones to end the bloodshed before it gets more out of hand; remember at this point Luca is dead, Paulie has been killed, Don Corleone is severely injured and recovering, and Bruno Tattaglia is dead.

Tom Hagen says to Sonny and Michael that they should assume Sollozzo will make another attempt at Don Corleone's life, based on his past actions, and thus they figure make him think he's going to meet for a deal, and kill him.

I'm curious as to whether or not that was the case. Sollozzo really has no options at this point, and he says that himself during his meeting with Michael. He's backed into a corner because his attempt on Don Corleone's life failed, and now he technically has cost the Tattaglia's the life of the youngest son of Don Tattaglia.

With the limited information we have to go by, do you think that Sollozzo really was wanting to make a deal and get out with his skin, or was he attempting to stall for time to make one final attempt on Don Corleone?

Also, if Sollozzo really was looking to make a deal, and instead of killing him Michael had listened and the Corleones went for it, what do you think the outcome would be? Personally I think it would transpire much as if Don Corleone had agreed to finance Sollozzo's enterprises in the first place: That is, Barzini and Tattaglia would use their vested interest in the drug trade to increase their own power, while the Corleone's power took a bit of hit. Eventually, maybe a couple of years down the road, Barzini would have made his move.