After years of waiting, the delay is officially over. As we predicted, Blizzard Entertainment announced today Diablo III‘s release, slated for May 15.

Those of you who have been anticipating the sequel to the successful Diablo franchise can pre-order Diablo III now, but the downloaded version of the game will be encrypted and won’t be unlocked until the official release date.

“After many years of hard work by our development team and months of beta testing by hundreds of thousands of dedicated players around the world, we’re now in the homestretch,” said Mike Morhaime, CEO and co-founder of Blizzard Entertainment, in a statement. “We look forward to putting the final polish on Diablo III over the next two months and delivering the ultimate action-RPG experience.”

Players will be able to select from five classes: barbarian, witch doctor, wizard, monk and demon hunter.

“Battle.net also provides a secure infrastructure for the Diablo auction house, a feature-rich marketplace that Sancutary’s heroes can use to trade their hard-earned treasures. Players will be able to buy and sell weapons, amorn, and other valuable items in the auction house in exchange for in-game gold,” Morhaime adds. In a novel strategy incorporating micro-purchases, Blizzard will offer the option to be reimbursed real-world currency from sales in its auction house. These funds can be used toward other Blizzard games, or for cash through a third-party payment service, like Paypal.

Fans who prefer to purchase the game from retailers can do so in the United States, Canada, South Korea, Australia, New Zealand, Taiwan, Hong Kong, Macau, South East Asia and Europe. For those of you located in Mexico, Argentina, Chile and Brazil, Blizzard will make Diablo III available digitally via Battle.net.

The game will be made available digitally and as a DVD-ROM package in Windows XP, Windows Vista, Windows 7 and Mac with a retail price of $59.99.

A special alabaster-white Collector’s Edition to be sold in participating retailers will include the physical copy, a behind the scenes two-disk set, the Diablo III soundtrack CD, the “Art of Diablo III” book, a 4GB USB soulstone including both Diablo II and Diablo II: Lord of Destruction, a Diablo skull base and exclusive in-game content.

As a promotional offer, expiring on May 1, 2012, Blizzard will throw in Diablo III for free with the purchase of its Annual Pass to its ailing MMORPG, World of Warcraft.