At "participating retailers, exclusively in Australia and New Zealand" for the price of AUD$89.95/NZD$99.95. Partly due to the fact that Australia is a playable civilisation for the first time in the series, which means the Deluxe Edition will come with all additional civs released so far -- including Australia, Persia, Macedon, Poland, and the Vikings Scenario Packs.
Plus, two additional Civilization & Scenario Packs that will be released later this year and focus on Africa and Southeast Asia. Civilization is one of those games that you kind of always need to make time for, and the Deluxe Edition is perfect for those that haven't got around to picking this up yet. Or are still playing Civilization IV. Like me.