Unfortunately, I don't think any Americans will be winning, but they're moving up the ranks. If you're looking for inspiration, click HERE to read about Mary Beth Ellis, one of the US's top iron-distance athletes. She broke her collarbone a month ago but is rehabing and staying positive to make the start line on Sat. Amazing what a lot of hard work and positive energy can do.
If you want to keep up with the media, check out Triathlete.com. Also, below are a few clips I recommend.
Breakfast with Bob & Paul (interviews with the pros): Day 1 / Day 2
Hines Ward becoming an Ironman. A pretty cool multi-episode series on YouTube.