I was under the impression that the 330s were to (eventually) be replaced by the latter 787s... I spose this will be subject to capacity requirements? I ask this because the 787 order as it stands doesn't look so crash hot if it replaces all 29 767s and all 22 330s. Some rough and quick maths shows a growth of 1 aircraft!
Having said that, I know QF have numerous options and purchase rights on additional 787s and that these are likely to be firmed up.