I occasionally watch the AFL, though I don't have any rooting interest. My wife doesn't understand why and thinks it's just men being stubborn about watching whatever sport happens to be on TV.
Regarding Australian sports more generally, I watched the Bathurst 1000 this past fall and I think it might be interesting to see the V-8 Supercars race in Austin in a couple of years. Be more interesting if NASCAR then ran a Winston Cup race on the same circuit. I'm not into NASCAR, but I think it'd be interesting to see how the two series stack up when running on the same circuit.