Blizzard were kind enough to send us some high resolution art from the presentation that Christian Lichtner - the Art Director of Diablo 3 - gave at the Game Developers Conference this year. See how Azmodan and Diablo were born, from concept to finish.
Below are images that display the conceptual design of the armor sets for each class, as well as the variety within a single class (in this presentation - the Witch Doctor).
Azmodan will be one of the bosses in Diablo 3 but how did he reach his current form? Lichtner provides slides following the evolution of the current ruler of the Burning Hells from a 2-legged monster to the humongous blob of fiendish royalty that he is now.
The namesake of the franchise - the Lord of Terror himself - has taken whole 13 slides, depicting his change into the form that we'll most probably see in Diablo 3.
Apart from being a super effective tool of elevating the hype even higher, some of them make for sick wallpapers.