I seriously doubt there will be a coach section on these planes for such long ranges. This is just a repackaging of the BBJ for use by airlines. In order to get the maximum range it is necessary to put in belly fuel tanks in the cargo hold. Of course doing so decreases the available cargo space available for cargo passenger luggage.
Lufthansa operates a flight from Dusseldorf, Germany to JFK using a BBJ. After 9-11 they still had demand for business class traffic for that route but not enough economy class to justify continued operation of an A340 or A330. Their BBJ flights have just 48 seats configured as business class. KLM operates a similar flight from Amsterdam to Houston. They already have several other flights with a combi (freight and passengers on the main deck) 747 and 767's. They don't need anymore seats for economy class passengers on that route so in order to have more frequency on that route for business passengers, they also operate an all business class BBJ.
My guess is that ANA wants the 737ER to fly high yielding passengers on long thin routes where there isn't enough demand for economy seats to justify flying larger aircraft like 767's, 777's, or 787's.