Let's go crazy and imagine a strange mirrorless box referring to old time TLR with a tactile screen you can slide on the top of the box and a square sensor and a K mount to adapt most of pentax lenses.
A squared FF would be ok for most of DA lenses with minor post processing which is common, even for luxury products like leica M digital rangefinders.
An autofocus TLR with tactile screen, made by pentax !!
Rangefinders leads to my second idea which is the release of another screw mount pentax lens based on limited lens (or another)
43 limited was a hit an let pentax name shine in the rangefinder world.
Moreover, today, it would be much much more welcomed with the EVIL market (m39 lense are very easy to adapt).
31 would be welcomed !
But it is for far future