I've been having some great fun over the past year or so perusing the "rumors" section.
And I suppose that if I had more sense, I wouldn't be making one of my first posts in this section, but this is the first "K3D" rumor I've seen that makes some sense.
Pentax keeps all the DA lenses - this is consistent with the "roadmap". All you need is the detector & some software changes.
The up-front investment by Pentax is low (they don't need to bring out a new line of FF lenses) and are instantly differentiated from Nikon, Canon & Sony. They can bring it out in only one high-end model (like going from CCD to CMOS in the K20D), and if it doesn't sell, well, no real harm done. But the possible benefit is huge.
The rumor is probably BS, but it's possible...