So I wonder what the first two 789 will do for the 3 or 4 months it's in service before starting PER-LHR?
My guess is the later MEL-LAX-MEL currently operated by the 747.
As a side note, I had heard that DFW-MEL is a stretch even with only 236 pax. Although a similar distance to PER-LHR, the mean (head)wind component at best is significantly greater than forecast for PER-LHR.
Given the number of initial aircraft, I suspect that the PER-LHR may not be daily initially, thus the 380 will continue to do MEL-DXB-LHR for a while - unfortunately (the DXB bit that is….)