According to a job posting on Gamasutra, Blizzard is hiring a "Senior Software Engineer Console Network" to work on the Diablo team. It's a full-time position that will be in charge of designing and working on network systems for a console title. One of the requirements for the job is that the person have worked on a major Xbox 360 or PS3 title and have a good amount of experience with PSN and Xbox Live.
While this is not the first indication that Blizzard is working on a console version of Diablo III, it certainly lends credence to the notion that the company is actively working on it. The studio previously said that the title "is probably coming to consoles."