I don't think anyone would disagree, I certainly don't disagree that a fully kitted out KC-30A is going to be much more useful that a standard A330-200, but I think there are two totally different questions here.
And it comes down to the ownership status of the VIP fleet, as currently is the case with all the airframes operated by No 34 Squadron, they are leased and not owned by the Commonwealth.
If the next group of airframes (large and small) operated as VIP aircraft are leased airframes, then I wouldn't imagine that we would see one or two fully kitted out KC-30A's (with VIP interiors), being leased by the Government, just can't see that happening.
If on the other hand the Government invests the dollars in owning the replacement airframes for the BBJ's, then yes lets hope they are fully fitted KC-30A's (with VIP interiors), but if they are going to be leased airframes, then one or two commercial standard A330-200 would at least see a reasonable amount of commonality with the KC-30A's.
Anyway, when the new DWP is handed down soon, hopefully that question is answered.
I'm pretty sure the two ex-lease aircraft just bought will constitute the large VIP aircraft. I can't see any more A330s being bought just for VIP on top of those. If they did though, I would be amazed if they bought more aircraft and didn't modify them to be tankers as well. It just makes too much sense - the RAAF would be all for it, and so would the politicians as it would mean they could pretend they are simply flying on normal Air Force aircraft, saving the tax payer money, as opposed to dedicated luxury tax payer money wasting jets. You would certainly never know the difference - the only thing different from a normal A330 and a MRTT on the inside is the presence of a small room for the boom operator just behind the cockpit.