Diablo 3's mysterious launch date has been released, and is scheduled to launch on February 1, 2012. At least, that's what a Best Buy in Rochester, Minnesota believes. Joystiq reported that the Best Buy had displays of Diablo 3 showing a February 1st launch for the game along with a countdown time. Below is the image, courtesy of Joystiq.
In addition to the date, it looks like Best Buy is planning a midnight launch event (at least at that location). The Diablo 3 product page on Best Buy's website is also showing a February 1, 2012 release date.
The latest rumors we heard were of an "early 2012" release, but that looked uncertain due to a delay in Korea that could interfere with Blizzard's goal for a worldwide release.
In an update, Joystiq pointed out that UK retailer Gameplay is showing a February 3, 2012 release date for Diablo 3.