For me the 645D project is certainly Pentax' star: great lenses, great camera, great past (lenses), great legacy, and tons of adaptable stuff. I don't care that much about FF and all the other offerings. A well positioned 645D system would re-establish confidence in the brand and its leadership, and this would have a trickle-down effect on smaller systems. In fact, with the 645D and the K-5ii Pentax has all it takes to appeal to a broad customer base. Don't understand the FF hype.
In the next couple of years, the 645D system would need a few more new lenses, the wide angle zoom and perhaps a wide angle shift lens. Maybe they even can adopt Schneider's 120mm APO macro. A longer tele macro in the 200mm range would be unique and imminently practical, especially with image stabilization. Now that's something I'd spend my cash on. Their existing 300mm and 400mm lenses are outstanding and don't really need much updating, and beyond that, hands down, FF telephotos might have an advantage in most situations. Finally one fast portrait lens, 2.0. Around 120mm. Pentax has never done that. Don't know why.
. My wish list. I know Radu you can influence them.
And even if not, the Pentax 645D rocks!