As for the Northeast Corridor, there really isn't enough NEED for true high speed rail. The trains already run fast enough, they carry heavy loads, and the stations are too close to really benefit from any greater speed. Right now they are dealing with the bottle necks - the bridges in New York, and the congestion in Southern Connecticut and New York. The next thing they need to work on is station access - the stations may be convenient for those in the city itself, but is terribly inconvenient for suburban dwellers because getting to the stations is so difficult. Once they fix that, THEN they will need to build a new route, because there just isn't more capacity with what they have now.