Originally posted by B. B. Cheese:
The only parts I don't care for really is they talk a lot more about Lucy Mancini and Johnny Fontaine a lot more and also they have that abortionist, maybe he wasn't included in the Godfather movie because of the whole Vincent Mancini ordeal. 
I think they cut the who Lucy Mancini/Jules Segal sequence from the movie, as well as 97% of the Johnny Fontane saga, and even the Nino Valenti/Deanna Dunn incident is because they weren't relevant to the plot as a whole. Vincent Mancini/GF III wasn't even thought of when GF I was being made, so that idea is illogical. We see the beginnings of the Johnny Fontane saga, he is a repeating character in the films, but his story in the film is meant to show the reach of the Godfather's power. And Nino Valenti wasn't included because it coincided with the Fontane saga...and Deanna Dunn WAS included in GF II, but as Fredo's wife.
