Boeing has made a great success to the 77W which is clearly visible to the ordering statistics, hence the time differential they've been available. The 77W as hit the sweet-spot for long-haul operators and seems to be a substitute to the B744 for many airlines.
I see that the 77W will be the first model to get a minor or major change, just more efficient to focus on i guess. The B77W is simply the better choice for most airlines.
Despite the B748, I do think the B748F will do significantly better.
