Anyone familiar with old pre-electronics carbureted engines knows that getting one to work well across a wide range of operating conditions and speeds is not a trivial matter. Thanks to computer brains today's engines mostly operate smoothly and seamlessly from a 600 rpm idle up to 7,000 rpm and beyond. 

The dynamics of moving air and fuel, combusting it and then getting the exhaust out takes a lot of very careful engineering and mechanical systems have severe limitations one of which is the valve-train. That's why engineers have been working to eliminate the camshaft from that process. They've already developed mechanisms to adjust the timing and lift but there is only so much when the valve stem/lifter has to ride up and over the bumps on the cams. 

Engineers everywhere have been developing actuation systems that can individually manage each valve and provide the optimum lift and duration for each cylinder. Lotus had an electromagnetic system in the early-1990s. Unfortunately while these systems actually work, the actuators also require a lot of power to run. That means the benefits of improved valve control are lost. Sooner or later however, someone will develop a system that is more efficient. I don't know if this pneumatic system that Koenigsegg is developing is the one, but it's an interesting video.