Microsoft is currently working on a Mixed Reality wand tool for its HoloLens. The company has already filed a patent which shows a simple, long, hand held device. The device also has a finger guard button and a trigger.
The device is similar to other Virtual reality controllers which are available currently for the HoloLens. The company had filed the patent on 1st June 2016 the day when it released the video about the MR experience.
The company is also working with other companies to involve them in development of both the HoloLens and MR since it wants the product to be as useful in design, construction and other sectors.
Microsoft wants to make HoloLens more usual for users who play some of the most complicated games and hence developing a wand like controller is always a better idea for the company. We would need to wait and see how successful will the new Wand like controller be with HoloLens after its launch.