I herewith provide genuine information from a roundtable discussion.
It was published by German "fotoMAGAZIN 4/2008" and I give the answers to question #1 (out of 9) from participants Pentax and Samsung (from 7, the other 5 were Canon, Leica, Nikon, Olympus, Sony).
Question:
"What sensor format (FourThirds, APS, Full Frame) will play the major role in the years to come?"
Answer Gabriele Remmers, Marketing Communications Manager Imaging systems Division Pentax Europe:
"The APS format has already established as the suitable format for the mass-market. We believe that this format will continue to determine the majority of the SLR market. This is why Pentax will, of course, bed onto sensors of the APS format. On the other hand, the Full Frame format will not be able to establish itself in the mass-market because of reasons of cost."
Answer Ernst Thürnau, Marketing Manager Samsung Opto-Electronics:
"The terms APS and Full Frame have been established in the heads of users since the times of analog film photography. They represent quality, maybe good old quality. In any case they are known terms and have a decisive advantage over the FourThirds format -- and if in people's perception alone."
[Translation: myself]
I see a subtle difference in the two answers: Pentax says no to FF whereas Samsung says both are better than FourThirds.
By this, Samsung admits that the form factor does play a role for market success and that in the future, it may be that only FF stands for "good old quality" (which IMHO is the case already today).
My conclusion: Samsung will urge Pentax into making a FF body.
Disclaimer: both representants may have no clue about what they have been talking about...
BTW, everybody else except Olympus was positive about FF. And you won't want to read Olympus statement
P.S.
Could everybody please refrain from the usual emotions
After all, it is a simple engineering question balancing cost vs. image quality.