China Southern already operates the A346.
As for emerging markets, both the 777ER/LR series and the 345/6 are overkill. Airlines instead may not buy them specifically for range, but their payload capability.
But money talks. These planes are so prohibitively expensive, that an extremely strong business case must be made for them.
I dobut you will see the A346 in the QF fleet. The 777 seems a more likley option. However the 743's have just been brought back into service but they will most likley be phased out whe then A380 arrives and routes that tha 743 flies will be replaced by 744's eventually.
Qantas will hold onto their 744's for quite a long time. The need for either a 345 or 772LR is always rumoured, but doesn't make too much sense at the moment. The case for either is, by far and large, a wet dream for most Qantas fans, IMO.
And for some reason, everyone on this forum seems to think that every airline in the world can afford 777's. Good for speculation, perhaps...