I have seen it recently on Conan. He visited Australia and participated in a practice. More comical than anything, but it does definitely have more action to it than American Football.
Catching on in the states? I doubt it. The field dimensions alone would rule out a lot of areas, but I am reading about different field sizes for different ages. Even normal rectangular fields. And those run a bit smaller than football fields (about 10 yards smaller)
The hits look more vicious because they aren't wearing pads, but they tackle differently too. Just like in rugby, they are trained to go for center mass.