The more I think about it, the 645D is pure Pentax:
* Inexpensive. Not "cheap," but not pointlessly overpriced.
* Especially considering what you get. It is, as far as I can tell, the first
MF DSLR with dust reduction. Weather sealing. It's stuff that the other manufacturers haven't really bothered with, that doesn't (in the grand scheme of things) cost much to implement, but Pentax has been the only one with the balls to do it.
* In that sense, it's obviously true to the original 645's
raison d'etre: a miniature field camera. It's inexpensive, tough, easy to use (it's got scene modes, for gods' sakes!) and compact.
* Students are going to love it.
There is, however, one thing that is very, very un-Pentax-like about it, something that takes bucks one of the grandest Pentax traditions and micturates all over it:
* The 645D will probably have best-in-class
AF - WE'RE ALL DOOMED! THE END TIMES ARE UPON US!
Here's some food for thought:
Canon ID Mk IV Dimensions/Weight: 156x157x80mm/1230g (with battery)
Pentax 645D Dimensions/Weight: 156x117x119/1480g (with battery and 2 SD cards)