Advance the cropping tool

I'd love to be able to change the shape of what im cropping with the cropping tool. Instead of rectangle or square shapes... I'd like to be able to create my own shape as to what to crop. Perhaps this could work in line with an improved tracing tool? But cropping is often something you need to do quickly. With windows surface tablet or studio, the stylus could be used to draw what you want to crop, instead of having to use a more complicated and unsophisticated trace and crop.