My guess is Pentax would be happy to be able to do a product refresh.
Well, it may be late now to do so.... The original (film) Pentax 645 had two crucial handicaps with respect to competition at the days: 1. They had the longest mounting distance by far 2.There was no interchangeable film backs...
With the digital version of the camera, they decided to keep the old mount
and use a much smaller image area than what the lens mounting distance is capable to serve (the lens mounting distance of the P645 is enough to serve a 6x6 image area). I think they would be much better off if they had gone for a much shorter mounting distance with the introduction of the digital body and just use adapters to attract the old customers/owners of lenses. I'm sure if Fuji will ever enter the MF market, it will be a much more modern approach...
IMO, Fuji won't be using the Sony sensor (filter converted or not) if they do enter the MF market for four good reasons:
1. They are among the older image sensor makers (with revolutionary sensors at the times) in the world and thus they would like to differentiate them selves from competition.
2. Unlike their mass production production products, they are traditionally known to be innovative when it comes to MF products.
3. It will be a good chance for them to enter the professional video market with a hybrid product as to support their cinema lenses further (especially now that the best cinema camera in the world - the Alexa 65 -
is using their lenses...4. It would be a good chance for them to sell the sensor to other makers that would like to differentiate themselves from the "Sony sensor domination" and thus to minimize the financial risk.
I think that Mr. Takashi is very careful with his end words : "We have a good history in the medium format market, and I think we would be successful again. We have the technology to make a very modern and high quality camera, but right now we are only investigating." ...he said.