I always thought DiCaprio would make a good younger Sonny. I have only seen a couple of his movies, but he can act. Also, judging from his appearance and the previews I saw of Gangs of NY, I think he can pull it off. Plus he does have a young face and could play a "younger" Sonny.

I do know too, that Leo is part Italian as he was in Italy last year (or maybe longer) and was commenting to the media there, that Hollywood bigwigs wanted him to change his name. He said he was proud of his Italian heritage and refused to change his name. That scored points with me as well. Anyway, I know I stand alone, and am certainly open to others, but I still say Leo would surprise all of you and do a a great job.
IMHO

TIS

"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK

"War is over, if you want it" - John Lennon