This just in:
Pentax released firmware update for the K-50 and K-30 adding support for the new KAF4 mount with electromagnetic aperture control.

http://www.pentaxforums.com/articles/firmware-updates/pentax-k-50-firmware-v110-released.html
http://www.pentaxforums.com/articles/firmware-updates/pentax-k-3-firmware-v130-released.html

The camera bodies supporting KAF4 up to this point were:
K-70 native
K-1 via update
K-3II via update
K-S2 via update
K-S1 ditto

Lets hope it will come for the K-5/K-5II/K-5IIs too.