The 747SPs and eventually all Classic 747s are being retired and A330s are being acquired as part of fleet renewal though replacement isn't one for one.
The A330s are for domestic operations primarily. 763s and 744s are the real replacements for routes previously operated by the SP.
Also slated for retirement within the next year are the 762s which will be replaced by the A330s and 738s.
As stated QF is now down to 1 SP (the other one retired at Marana) and it is not being used very much though it is doing a few domestic routes such as MEL-PER and a few int'l (SYD-NOU, SYD-HNL)