I agree that there are a ton of great half-frame (and similar format) cameras already out there -- new and, especially, used. I don't see how Pentax can possibly top all of them -- or even come close -- without making something too expensive for the market to bare. I suspect, if the rumors are true, that they think there is enough interest in FILM, and to keep the FILM cost down, half-frame. There are already several halfway decent new half-frame cameras -- Kodak H35, etc. -- so Pentax would need to come up with something better, but who knows what. Auto-focus with a zoom? A smaller, lighter Yashica Samurai v2.0? That's my guess -- basically an APS camera (which is actually a half-frame camera anyway). Why not a Minolta Vectis 10 using 35mm film? Very small, very light, a better, faster lens, auto-focus, auto-exposure, built-in flash, tripod socket, zoom lens, self-timer, zooming viewfinder, DX coding, etc. -- basically a Samurai with a viewfinder instead of an SLR. Much less expensive.
It probably would sell pretty well -- but I'll stick with my Samurai.