ok, i have some more info:
It was the idea of taiwangun to make the pkm. They supplied a&k with schematics for the pkm and non-essential parts (ie. Grips, stock, ammo can, bipod) two years ago.
Release date - "spring 2012".
Battery is in the mag, bbs are fed through the bottom of the gun (where the magazine latches onto the gun).
What you're seeing on the photos is the complete prototype. The final version will have proper-looking plastic parts.
http://www.wmasg.pl/pl/news/show/172553 - feast your eyes.