I'll post up what I personally experienced with the IQ250 (amazing) a little later. Pentax is going to have a bit of fun in the near future, lots of press and photogs looking to try their product. I hope LensRentals picks up more of the 645 lenses and the Z, as they are the only Pentax MF rental shop I know of.
Unless there's a stockpile of gear waiting for this initial rush, I fear Pentax will have too much of a good thing. Manufacturing these items isn't a high volume business model, so expect to wait a while as they get their process up to speed. Toss in any service issues, and you could have a lot of pissed off people. Yes, now you can get a body with 3 lenses for $15-$18k, but that service and support that you've experienced with local dealers or with Steve or Doug isn't currently there (spares, experience, loaner gear, etc). It will take some time, and in that time I expect even more new products.
It is a good, but expensive time to be a photographer.