There's already a T2K setting for Australia. It's called,
Mad Max 2: The Road Warrior.
In all seriousness, I wish Leg had chimed in earlier, before I submitted edits to the KPSB. I would have loved to include a more detailed ANZUK Brigade OOB, and he would have gotten an add in the acknowledgments section of the updated sourcebook.
Anyway, I'd love to see an Australasia Sourcebook of some sort.
To get back to Chalk's original question, I'd like to play in a CONUS game. I'm really interested in how my own national/regional/local society and culture would be affected by the Twilight War. I love Poland as a setting, but there are so many good PbPs and campaign journals out there on the interwebs that it almost feels too... familiar now.