A little while back, I sent an email to the Pokémon Company International asking if Arceus and the Jewel of Life would be coming to the United States and asked if there were any delays, but of course they didn't answer back.
But there definitely has to be a snag somewhere, or some major priority change. For Australia to not only get to air the film on television first, but to get the DVD so much sooner than the rest of the (non-Japanese) world, something different is definitely going on. (It almost feels like the other countries lost a bet and Australia won, granting it the right to air the film / get its DVD first. xP )
Juliacoolo, where did you see it being stated the DVD would be released in Fall 2010? I must've missed that. xD