Today Jay Wilson has announced that he is moving on from the Diablo series. In a post on the Blizzard Forums, the former Relic Entertainment lead designer turned Diablo III game director said his goodbyes to the community, stating that he's moving on to new challenges within the Blizzard realm:
"…[W]hile it's been one of the most challenging and rewarding periods of my life, I've reached a point creatively where I'm looking forward to working on something new. The powers that be at Blizzard have been gracious enough to give me that opportunity. Over the course of the next several weeks, I will be moving off of the Diablo III project and transitioning elsewhere within Blizzard."
He does not go into detail about what his next project will be, and thus far no replacement has been named (though he does hint that the search will include looking to sources outside of Blizzard). He goes on to assure the fans that his departure will not slow the progress of the game's upcoming developments and that good things are in store for the future. Best of luck to him in his future endeavors.