Touch ID is an important feature for Apple these days as it is a main point of fullfilment of security requirements for iPhones and iPads, but it could be coming to Macs too. The idea is that Apple could use Touch ID for future Macs to Log In on your Mac. The recently filed patent by Apple can be put on a laptop, or even for desktop computers such as an iMac.
The patent also covers technology that is implemented in stand-alone desktop keyboards.
The Apple patent figure is illustrated below (it is the second image that we put above), it is a perspective of an electronic device on the keyboard that includes a finger sensor, giving it improved security. The patent extends to a future iMac where the Touch ID feature could be incorporated into the keyboard.
As is usual in this type of findings, most patents are not built into actual devices, that is, they do not come true. This could be another one of those cases. However as noted above, Touch ID is an important feature for Apple, and unlocking with just one fingerprint on your future Mac sounds very exciting.