Abortion (spoiler)
I think this film was brilliant and stands up well against the 1966 version.
But one plot point did bug me. In 1966, when abortion was illegal in the UK, the wife of his friend that Alfie impregnates goes through with the procedure, and the result is one of the most amazing pieces of acting in Michael Caine's career. In 2004 this film fudged the issue, despite the fact that abortion is legal in the USA and does have an affect on real people.
I really think they missed an opportunity here.