With Robotics;Notes in full swing, I don't think anyone was really expecting to hear word of another story from Chiyomaru Shikura. Unlike his past offerings, this one will not be a visual novel. It seems he is about to branch out a little and try something a bit different, as Occultic;Nine will be released next spring as a novel.
The new project was announced at Comiket 83, and other news is relatively scarce at this point. I'm sure that most of us will be hoping that the new story has more in common with Steins;Gate than it does with ChäoS;HEAd, and with a crazy supernatural setting and a cast that includes a doujin manga creator and someone interested in the dark arts, it sure sounds like things will get nicely weird and exciting.
I wouldn't be too worried about the lack of visual novel just yet. If Robotics;Notes was anything to go by, we might get an adaptation sooner than we think. But what about that 'nine' in the title? Okay, there will be nine characters, but what if there are also nine hours and nine doors?