Dear Pentax,
if I view the landscape correctly, Pentax needs to occupy a niche from which to survive and grow from.
I further assume that the K-mount backward compatibility is one of the company's greatest trump card. Even though the availability of a lot of classic and affordable glass to Pentaxians means that they are not as much forced to buy new Pentax lens products, I'm sure that sooner or later they will want to have some of the more modern (and in many aspects better) lenses too.
Therefore the decision to cripple the KAF mount on the K100D/K10D/K20D by omitting the aperture coupler must be considered to be questionable. While I applaud that fact that you can still use manual lenses with an extra press of a button, it'll be nice if that additional button press wasn't necessary.
I believe that either all, or all but the most basic Pentax DSLRs should have the aperture coupler OR that there should be a choice for the customer. There could be a normal model without coupler and a special model with the coupler. The latter could be distinguished by other features as well and if its just something cosmetic.
Make the special model a bit more expensive than need be and use the margin to reduce the price on the normal model. Then everyone's a winner. You only do not have the full backward compatibility if you didn't want it. And if you want it, Pentax provides you with the possibility to get it.
Many people intending to enter the DSLR market will ask their friends about which model to chose. The respective answer could be "Ask Terry, he is really serious and has myriads of lenses" and the reason why Terry has so many lenses is because he is a Pentaxian and can a) afford them and b) use them optimally on his new DSLR.
BTW, is it really true that Pentax has run an advert promoting Pentax cameras as good for shooting sports? That'll be really hilarious because if there is one thing the Pentax line doesn't excel in, it is speed. I can't help but imagine a customer walking into the shop saying "I want a Pentax because it is good for shooting sports" with the shop staff's immediate reaction being to fire away with two Canikons left and right of the customer's head until the customer asks whether you can shoot a movie with them.
I think Pentax should capitalise on one of its greatest assets and that means that an uncrippled K-mount should be available at least as an option. Pentax's natural niche appears to be to be more affordable with an emphasis of classic photography. The availability of a coupler could allow new photographer's to enter an affordable hobby (with old and used lenses used in an uncompromised way) and then later grow, buying new lenses as well.
Imagine how reviewer's like Shawn Barnett would rave about an uncrippled KAF mount. Reading positive reviews from enthusiast like him (->
Pentax K100D Digital Camera - Full Review - The Imaging Resource!) helped me to decide for a Pentax product.