I have an old Sony Alpha 300 that I just picked up. I'm learning about the difference between the A-mount and the E-mount. As I understand it so far, A-mount is for the DSLR and E-mount is for the mirrorless cameras. Sony appears to be getting away from the DSLR and concentrating on the mirrorless. Will they get away from the DSLR completely and let the A-mount go obsolete?