K10D -sharp or not?

Don't lets get tied up in knots! It is a complex issue with various factors having various degrees of effect. Yes, the anti-aliasing filter will have an effect on sharpness and resolution (not the same thing), as will the processing, the lens, and indeed the final software operations performed by the user. In theory, the IR filter will also have an effect, as it removes stray light invisible to the eye but very visible to the CCD and causing, potentially, light scatter.

Interesting how many variables there are, and how different manufacturers decide on a different balance of solutions.

The CCD itself probably has less effect than we think, because it may well be the same CCD in many different makes of camera. Canon of course use CMOS, which has different advantages and disadvantages of its own.

I love the complexity of photography!

Pentax themselves have made it clear that in their design for the K10D they were aiming to capture the best image and leave sorting out final sharpness and noise reduction to software post processing which puts creativity into the hands of the photographers and not the camera designers.

I do not have any quibbles about the sharpness of the images I produce, now that may say more about the state of my eyes than the camera!