i think Americans should see this movie if for no other reason than to get a better sense of Chinese culture, values, and spirituality. This movie could be the first major Chinese film to compete with Hollywood films. Cinema could be the new arms/space race.
if i had to summarize the movie in one line, i'd say it's the story of a once criminal's spiritual journey to enlightenment that redefines the notion of "a kung fu movie." you'll laugh, you'll root for the good guys, and you may cry at the end (i did, and i am a guy).
and if you're concerned about violence for your children, there's plenty of it for them. (j/k) but seriously, read some of the threads on the message board about that.