I wonder if they'll convert the A330 for major Prime Ministerial international trips (where they want to take the press corp along) and quietly keep the BBJs for more discreet, more local uses.
I suspect that's exactly what they'll do, as it was back in the 'old' days when the BAC 1-11s, DA-20s and HS-748s did the majority of VIP flying, and the B707 was called in for longer overseas trips or the odd election campaign. I also suspect they'll need to convert more than one KC30A to fill the role, firstly to provide a spare and secondly to cater for the Opposition's requirements during election campaigns.