The 767s will be around for atleast another 5 yrs, because a decent replacement type has yet to be found. Perhaps the 787 will fit the bill. The 767 is a very flexible machine, efficient on domestic routes, and able to lift a decent load off Rwy27 in Melb and then fly nonstop to Narita. The A330 has higher payload restrictions.
The last international 767 route will be CNS - NRT, and in a year's time the 767 will be an all domestic and tasman fleet. Incidentally, most of the Tasman flying is done by OGD/E & F. These aircraft are around 15 yrs old - amongst the oldest 767s in the fleet, and yes, unfortunately, are getting a little shabby in the cabin. Conversely, some of the 767 are fairly new; I flew AKL - SYD the other day in a 767 built in 1998.
WG.