Ask most camera-industry experts and they will probably say that mirrors are on their way out of the camera game, at least in the long term. But for right now, DSLRs are still offering some of the most advanced tech available. Recently, Canon released their 50+ megapixel 5Ds camera, which required some changes in the system responsible for flipping the mirror up and down during shooting.
The new system exists in the 5Ds as well as the 7D II and uses a motor rather than a spring to flip the mirror up to take a shot, and then back down when the shot is over. As a result, the mirror doesn’t “slap” inside the camera as hard, which is meant to reduce any vibration it would otherwise cause.
While it may seem crazy to think that a small mirror like that could cause camera shake, it’s actually a well-known phenomenon. In fact, many DSLRs have a “lock-up” mode, which raises the mirror before the shutter is pressed so if you’re doing a long exposure on a tripod or something like that, you reduce the risk of camera shake.
The need for something like this is also heightened by cameras with very high-resolution sensors. With all those pixels, even small amounts of camera shake can produce unattractive blur, so minimizing mirror slap seems like a worthwhile pursuit.