Originally posted by Aristophanes You cannot have k-mount mirrorless in a smaller body than a K-r. The k-mount is an SLR mount. The option exists for an adapter, but it will add substantial bulk and cost.
This is an announcement of a new mount.
Why not? The main size advantage of a mirrorless camera is the reduction of sensor-to-mount depth (and consequent potential reduction in lens size), not so much the mount diameter.
Hence my suggestion: It can be
collapsible - allowing for two different sensor-to-mount distances - one for new MIRC-exclusive lenses and one for legacy K-mount lenses (although this is just a wild thought. Probably you're right and they won't do this).