This is the reply I got from Lionel today about the N&W set.
Hello Mr. Cole,
This product is anticipated to ship to our distributors next week. We cannot say when the distributors will receive this nor when they will ship to their dealers.
We cannot say if there are plans for a 2-car add-on. The Lionel Marketing Department cannot share plans for future product. We apologize but because of the nature of our business, future product is made official at the introduction of a new catalog.
Sincerely,