The problem with a lot of these long distance runs (to AKL/SYD etc.) is that they take more than one plane to operate, meaning extensive ground (down time) at the destination. The CO nonstop EWR-HKG sits in HKG for about 20 hours doing nothing. This is clearly not a good use of a $250 million airplane!
At the Houston DO, CO execs stated that this was an important consideration in picking routes for their 787s. They admitted IAH-Asia was their first choice, but the down time was a very big issure and would have a big part in their final allocation of the new planes.