Lloyd's findings in short (DAP is subscription based but a lot conclusions are in the blogs like this):http://diglloyd.com/diglloyd/2011-01-blog.html#blog20100104Pentax120f4
The new 55mm and 45mm FA are bad out of the center 1/2 (55mm) and 2/3 (45mm) area.
The 75mm and 200mm are very good at least (hard to focus).
The 45-85mm zoom is excellent, and way outperforms the 45 and 55 primes. (no surprise -- after careful testing I sold all my Pentax 67 prime lenses in the range of the two zooms.)
The 120mm macro is outstanding, razor sharp corner to corner even wide open at f/4.
He is going to test more (150mm, 80-160mm zoom, and some Pentax 67 lenses through the adapters, at least).
Else where on the web you can find sample images from the 35mm and the 33-55mm zoom. They look fine and 16-9.net tested and found the Pentax 645 35mm the best wide angle in MF field. Now lacking are sample images and reviews of the 55-110 and the 150-300 zooms, and the long (300mm ED IF, 400mm ED IF, and 600mm ED IF) optics.
Pentax released a new firmware (V1.0.1) for the 645D to support SDXC cards, and promised firmware changes in the future for tethered shooting as well as new lenses including a new wide angle, rumored a 25mm/f4.
About the 67 adapter on 645 and 645D -- you can use the 67 lenses exactly as the 645 MF (A) lenses:
“Pentax has two medium format camera lines, the Pentax 67 and the Pentax 645. Unique among camera makers,
Pentax has designed the systems so that the lenses from the 6X7 camera can also be used on the 645 body. They
manufacture an adaptor for this that retains autodiaphram and open-aperture metering capability. Put it on a 645
body and you can use all your 67 lenses pretty much as normal. (Contax allows their 645 lenses to be used on the
N series 35mm cameras. Pentax has an adaptor that allows medium format to 35mm as well, but in this case
autodiaphram is lost.)”
You can also buy small gadgets like this:
Pentax O-RC1 Remote Control
"A simple item that didn’t come with the 645D camera was a remote control. The Pentax O-RC1 is a simple device that allows you to fire the shutter without pushing the shutter release button. This is great for self portraits and family photos as it avoids the self-timer dash. More importantly for me, it means I can eliminate any micro wobble that may occur when pressing the shutter release button on a tripod mounted camera. As a bonus the remote control is waterproof, which in rain soaked Okinawa is probably a good idea.
The remote control also works with other 2010 Pentax cameras including the Optio W90."
Lloyd's DAP and other detailed paid references (such as digital infrared) are worth the subscription cost to my opinion.