Younger, faster Euro's buzzing around on a bigger sheet of ice caused problems for the US defense. Our team just wasn't defensively sound, and neither was our goaltending.
I doubt we'll ever see the days of amateurs/college players only in the lineup. Some of the younger players were great - Blake, Gionta, Gomez, Drury, Leopold - and have a great future wearing our flag in international competition. Hopefully we've got some good netminders coming up in the future.
It's going to happen sooner than you think. The current agreement between the international hockey federations and the NHL expires after the 2010 Olympics, and I don't think it's going to be renewed after that.