What they can do is what happens in Canada, most/all cable + Sat. companies broadcast the major US networks but say fox is showing Prison Break and a Canadian channel own the Canada rights then they bring in Sim subbing. Where the canadian channel gets it's broadcast put in place of Fox's. This way they show Canadian adverts instead of the US feed. I think this would work here. The only thing to screw this up is that Aus + NZ will need to broadcast the shows at the same time and due to the time difference I am sure they can do a -2 for NZ (like History channel). If the FTA own the right's then it is no problem.
I remember that you could either watch it on CTV with Canadian Ads or you could watch it on whichever ABC/Fox/NBC feed you received with the American ads?
A similar situation probably wouldn't happen here, unlike the USA and Canada, our time zones don't match - The 'merged' Foxtel/Sky could simply keep the feeds of 7/9/Ten/*others and One/Two/3/C4 on different transponders as to not interfere with the programming rights if the individual channels.
It certainly would be interesting to see what would happen with the additional channels (I'm another person who wants Boomerang!) and to TCLs cable network. IMHO I think that the InHome TV label is uh...bland.