Although a bit late, Mark has finally given a peek into the system, dubbed Jarvis. The system currently lets him do several household and personal tasks, including turning lights on/off, playing music based on personal preferences, open the front gate of house, make toast, and wake up kids.
The following gif shows Mark playing with the lights of his living room using Jarvis:
The Facebook CEO has spent somewhere around 100-150 hours on this project. He has in large part relied on a collection of Facebook tools that helped him with the development of Jarvis' image and voice recognition capabilities.
However, the system is still nowhere near to being a polished product. For example, the way it responds to voice commands isn't consistent yet. Also, when he announced Jarvis, he said that it'll help him "visualize data in VR to help me build better services and lead my organizations more effectively." The VR thing isn't there in the system at the moment.
Mark makes it clear that he doesn't have any plans to make this a Facebook product, but will likely publish a summary of the project, hoping that it'll help improve the publicly available systems.
More about jarvis:
Source: Facebook