Dan,
Hmm... I don't see the A359 replacing the 77W on many long hauls (too small). Maybe one or two here and there where the demand is lesser, but until the -1000 comes (which is a ways off) l don't see the turnover happening anytime soon. Even then, I see a blend of A350s, 77Ws, and 77X. The A359 seems likely to take over A340 routes first and then, with any luck, open some new thinner routes, which is long overdue.