He's leaving ARM in good shape. Its revenue was up 21 percent in the last quarter, and its profits up 16 percent, outgrowing the semiconductor market as a whole. Almost 9 billion ARM-based chips went into devices last year, including digital cameras, thermostats, the GoPro wearable camera, and even drones.
Intel is working hard to design chips that can match ARM's power-saving characteristics, but it has yet to make much of a dent in the all-important phone and tablet businesses.
It's not without reluctance that East is bowing out from ARM. "Obviously there's a part of me that would like to stay in this business forever, it's an incredibly exciting one to be in," he told reporters on a conference call.
It seems likely he'll be reappearing somewhere soon.