About market perspectives for the Airbus wide-bodies in the USA: Apart of USAirways - which is already known to be a future A330 operator -, Northwest is the most likely to operate A330/340s. Northwest has orders to 40 (?) A330s, but they have been deferred.
TWA also has orders for 16 (?) A330s, but I doubt they will keep them: they are right now ordering and receiving more B767, so an A330 order seems insensate. I would bet they will order some B764 in the future.
UAL have also been quoted: United could eventually order A330s (332s and also launch the 331s version) to replace the totally or part of the 762s and 763s, but there is nothing official about that. Although they would not offer commonality with the B777 fleet, the planes would offer the benefits of the commonality with the A320.
American, on the other side, said they could not follow their exclusivity contract with Boeing if this manufacturer don't offer RR engines for the B777s new versions. It means that AA could - eventually - order RR-engined Airbuses, such the A330-200 and A340-500, but I think it's very improbable. So, Northwest and USAirways seem to be the most probable A330/340 operators in USA. Apart of those, there are also some comments about America West interest on 332s but, once again, nothing official.
More information and opinions can be found on some topics already discussed here.
TP343, São Paulo, Brazil.
To SEA: yes, Airbus has 2 families concerning cockpit: the 300/310 one and all the others together (319, 320, 321, 332, 333, 342, 343, 348 and in the future the 318, 331, 345 and 345) in other family. About the 767 (except the 764), I'm not sure, but I think they don't have really an extensive commonality with any other Boeing product.