I agree with Joshua949, the 7E7 would be a great fit at American, they could replace the 757,767, & maybe even the A300 with one airplane type.
Northwest is leaning towards the Airbus models.
The 7E7 would make a nice fit at ANA, which is starting to lean towards twin engine Boeing models, they are phasing out the 747 in favor of the 777. The 7E7 would replace the 767 that they have.
The 7E7 would fit in nicely at Delta & help with reducing aircraft types. Just hope that Boeing does not require another type rating for the 7E7, this could be a deal breaker.
On a side note, I hope that my company gets a 7E7 simulator, we are getting the 737NG simulator next year, and the 7E7 would be great. I wonder what the visual is going to look like, this would be the newest kid on the block.