Tokina employees confirmed that a new Pentax full frame digital SLR camera is under development and prototypes already exist.
According to the employee, Pentax is reportedly developing a full-frame camera (he claims that a prototype already exists). He stated that all lenses developed will be re-branded under the Pentax name as it had been done in the past.
It seems that Pentax also confirmed their full frame DSLR camera plans in an interview with PentaxForums. Here is the video clip from the interview with PentaxForums.
Ttranslation/transcript of the video
In regard to full-frame cameras, at this point to be honest, even I also thought about whether we should make them or not, but right now I think that we should make them. Even within the company this idea had many opinions on it and some who thought it was a bad idea, but now many people are open to the idea of making full-frame cameras. The development of the technology is advancing and at this point it is being presented.