I wouldn't mind a FF Pentax myself but I can't see it happening in the foreseeable future.
Since being acquired by Hoya, the company has spent the last two years trying to consolidate it's position in order to simply survive.
With the K-7, and primarily the K-x, it appears to have done that.
It has actually stemmed the losses and reported a profit.
The 645D has been work in progress for about 4 years and although just released it is far too early to determine whether or not it will be a profitable decision for the company.
Instead of producing the K-x, if Hoya/Pentax had spent all that effort and more to manufacture a $2500 FF DSLR I think that decision in the current climate would have been the death of Pentax.
Why?
Because the market for a Pentax FF is still far too small to be a viable business proposition.
The K-x was a smart move at it has generated a lot of brand new first time Pentax owners.
Producing a FF instead of the K-x would have not brought enough new first time Pentax buyers into the fold and Pentax desperately needed to do that in order to increase its customer base.
Most Pentax FF buyers would already be exsisting Pentaxians looking to upgrade their APS-C DSLR's. The reality is, as it stands, is that is nowhere near a big enough market.
Most FF buyers would either be existing Canon or Nikon owners that are far more likely to purchase a Nikon or Canon FF than switch to a Pentax FF.
And besides, not many first time DSLR purchasers are going to buy a FF as their first camera anyway so that rules them out.
By producing the K-x instead Pentax has grown its customer base. That then may make it viable for Hoya/Pentax to look at a FF camera further down the track as some of these new Pentax owners first outgrow their K-x's... then K-8's(?) and then finally look at upgrading to something better (FF?) in the future.
However I am still not really even convinced we will still see a FF from Pentax as I predict we are heading towards a major global economic collapse within the next two years and people are going to be far more concerned about other things than spending money they don't have on a FF camera!
Yes folks batten down the hatches, the sh*t is soon going to hit the fan!