Nintendo CEO Satoru Iwata died of complications related to cancer on Saturday at the age of 55, Nintendo reports today. He had returned to work shortly after having a growth removed from his bile duct last June, but his condition declined rapidly over the past few days. The death leaves uncertainty about succession, and word is the company's next CEO will be faced with the challenge of completing Nintendo's belated entrance into the mobile market. Condolences to Iwata-san's family, friends, and many fans. A post on Kotaku (thanks nin) has industry reactions to the news.