I keep thinking Hugh Grant for Tom and Penelope Cruz for Cinzia, except she's from Spain, so I'm not sure how people would react to her casting. She just seems right for it, though. For Carolyn, I don't know.
I would love a remake even though I love this movie as it is. I think they should keep it very close to the original, but just modernize it a little. Just a little. It's the perfect family film. I hadn't seen it in years until just a few days ago (and again tonight), but realized that I'd wanted the same rug in the beginning title scene (where Robert is playing his harmonica and walking in a circle) for my son's (almost three now) room. Also, I bought him a harmonica for his birthday last year, and he walks around like that like a typical little boy; he could play Robert!

The movie Overboard starring Kurt Russell and Goldie Hawn was a loosely based remake of this film.

Give me a break.
Why on Earth do you want a remake?
What the Hell's the matter with this film?
NO MORE REMAKES.

I'd say Monica Bellucci for Sophia Loren's character. I love Emily Procter too, she would be perfect as Carolyn.
I'm a humane man but right now I could kick a kitten through an electric fan.-Frasier