OK, nothing ground breaking here to anyone who's followed rave toys such as flow staffs.
However, this tech has now been applied to fans that can be fixed to walls and used for advertising or to "project" 3D effects, making them ideal for clubs, home parties etc (provided you keep the blades out of reach).
Several companies make this tech, and whilst ebay versions start from less than £100 for vga versions, there are more expensive 4 blade HD versions and even professional level 4K versions available, with 65cm being a common diameter.
A video from Linus Tech Tips here of a 4k pro version. Might not really be either 3D or holographic, but it is pretty impressive and cool looking for a club, party etc (suggest you up the viewing resolution to 1440P or 4K):