Kmart Australia are to be giving out Arceus on November 5th to the 16th @ your Local Kmart Store
character on your Nintendo DS or DSi™
Bring your Nintendo DS or DSi™ and your
Pokémon Diamond, Pearl or Platinum version to your
local Kmart store between 5 - 16 November to receive Arceus!
Source 1: http://gamesites.nintendo.com.au/arceus/
Source 2: Page 18, Save This Summer Kmart Catalog (View Here!)
Giveaway Places List: Here!
Apparently, EB Games are also giving this Arceus out.