Well if we still had Bowen and 'the worlds best treasurer' Swan at the helm we probably would have a Budget emergency! Anyway......
Be interesting to see, if this does proceed, if the replacements for the BBJ's are standard A330's or fully fitted KC-30A's, I'd imagine that they wouldn't necessarily have to have the pods and boom fitted (bolt on, bolt off?), but as long as all the plumbing and other modifications are included, it would be a good way of having surge capacity to the KC-30A fleet available when required.
If I remember right when the original purchased was announced, way back when, there was an option for another three airframes, so two extra will go most of the way to fulfilling that.
As for the C-17A's, I remember seeing something the other week that the last C-17A has come off the production line at Boeing (assume it would be one of the '10 white tails' that Boeing committed to building?).
If the Government is interested in another one or two, I'd imagine that some discussions would already be underway if they are serious.
Wouldn't want to wail till mid next year for the new DWP to be announced and find out that all the white tails were sold!!!
EDIT: Actually I don't think the last C-17A is due off the production line till next year sometime, maybe it was the last to enter the production line, can't find the story I read recently!!