Textbooks: New Interchange

A lot of teachers use these books around the world. Some hate them
and some think they're OK. The thing is they have some great sections
and some really bad sections. On the positive side the layout of the books
are great divided into short sections which allows the teacher to expand in
anyway he or she wants. However the teacher's book is terrrible
as an activity resource; it merely provides some necessary back up
information useful on the first teaching. After that.... well who needs it?
One would have thought that with the advent of the Internet
textbooks such as "New Interchange" and "Headway" would have jumped
at the chance to give added support to teachers. Curiously,
they haven't. What are they doing? Living blinkered in ivory towers?
Could these textbooks go the way of the dinosaurs as teachers turn
to the net?