Fmulder points us to a video from the Bliz Irvine art museum, uploaded by BetaStarcraft, a Chinese site. This was apparently recorded last month, during the Starcraft II fansite summit, and it shows all of the Diablo 3 and Diablo 1 and 2 pieces in the museum, including the mysterious Black Soulstone one we’ve had such fun debating over the past couple of weeks.
The Diablo art shows up about one minute into the movie. The narration is interesting as well, since Casey, their tour guide, explains how the museum is run, and how the art themes change quarterly. Company awards also appear, as do the documents related to the famous original $15k loan Mike Morhaime got from his grandmother to start Silicone and Synapse. Casey also makes an appearance, despite her admonition not to photograph or film her. (She shows up around 5:30.)