Jetstar International is the Singapore Based carrier that QF will be opening up with Singapore based businessmen and investment co.s It is a separate airline to Jetstar.
Jetstar in Australia is not planned to operate any international sectors at this stage, however the possibility is there .... in the years to come they will probably do some flying to NZ.
Jetstar only services the Eastern States, one would think they would increase their domestic destinations (eg ADL,DRW,BME,PER etc) before they considered going international.