We know that something will have to replace the K-5. Chances are very high it will be APS-C. I thought this information sounded credible:
Originally posted by jpzk K-5 Successor Updates
There will almost certainly be a higher-end APS-C camera announced around the time of Photokina; there may be an entry level model as well. Although K-3 would be logical, I wouldn't count on any particular names - I think it depends on how many models Pentax is coming out with and how they are positioning them.
The FF model could be released any time in about the next 6-9 months - there's no concrete information as to when, or what the name will be. But we know some kind of FF is coming because Pentax all but said they were creating one last January. I don't think Ricoh had a chance to get the project going before early last fall, so it must have started sometime between then and January. Add 12-18 months for development and you have your time frame. Because of the market situation we know Pentax would prefer to shorten the time frame, but that doesn't mean it can be done. It could also be delayed because they have to prepare 2-4 lenses (whether their own design or someone else's, like Tokina's) - probably all zooms (e.g. 2 kit and 2 pro). The focal lengths would be so obviously FF they wouldn't even dare put them on the lens roadmap. As for the camera's name? It's immaterial right now - I could believe just about anything.
Actually, the biggest mystery to me is whether Pentax would dare announce a FF model more than 2 months before they can actually sell it? If not, the probability of hearing about it next month seems rather low. But I do believe that by December or January we'll begin to get some credible rumors, telling us it's near. But until then we know they're working on it because of what Pentax has said (and what they've refused to deny) about it - in fact, some representatives were so excited about the project they could hardly contain themselves! .
I know some people get "tired of hearing about FF," but denying it now is just as senseless as believing it was 2 years ago, when Hoya was clear they were
not working on one! If we can just stop denying it, we can all quietly wait and see how much longer it takes now.