Australians had to wait the longest for their DVD, but they got more than anybody. This is a 2-disc set with lots of tasty extras. Oz Browncoats also get "A Filmmakers Journey," a Joss Whedon Q & A Session (filmed at Sydney's Fox Studios), Extended Scenes, "Take a Walk on Serenity," where the cast and Crew take us on a special tour of the Serenity ship, and "The Green Clan," a featurette on cinematographer Jack Green.
There are also some limited editions versions available from different outlets. EzyDVD has a collector's tin (left), and JB Hi-Fi has a slipcase edition (right). Same discs inside, just cooler containers.
Also, according to the Serenity Oz website, if you purchase the DVD at either Dick Smith Powerhouse stores or WOW Sight & Sound stores (in QLD and NT only) and get a free mouse pad. I believe it's walk-in only, check the links for a location near you.