Originally posted by ManuH Because that would make absolutely no sense at all. More expensive than APS-C, lower performance than FF, new lens line, you get the picture... Besides, no one make APS-H sensors but Canon. And they don't share their sensors.
I've been wondering about APS-H as well. While I doubt that Pentax will go down this path, it's not obvious to me that this format is such a non-starter as you depict it.
More expensive than APS-C? Sure, but better performance too.
Lower performance than FF? Sure, but considerably cheaper to manufacture.
New lens line? Not necessarily. FF lenses would be entirely suitable, and some APS-C lenses might be OK as well.
Besides, no one make APS-H sensors but Canon. If Pentax approached either Samsung or Sony with a firm order, it would almost certainly be possible. My understanding is that APS-H sensors can be manufactured using the same processes as APS-C -- they just divide the sensor wafer a little differently. FF sensors, however, are considerably more expensive to manufacture.
As many other people have suggested, $1500 is the magic price point where significant numbers of people feel that they can afford a DSLR body. FF bodies will eventually be available at that price point, but not now. In the meantime, APS-H may well be a perfectly feasible intermediate format that can be delivered at that price point.
If APS-H is to be adopted as an intermediate format on the road to affordable FF, there's no need to develop specialised APS-H lenses. Instead, Pentax could steadily develop FF lenses that users would happily buy, secure in the knowledge that these same lenses will still be viable if and when they migrated to FF bodies.