http://www.pentaximaging.com/about/press/283
Via: Post @ Pentax Forums
The price cuts for the 645D, K-01 and the Q are quite significant.
On the other hand, I can only see similar major price cut for the 645D only at Japan, in 100,000 Japanese Yens, which is yet very close to the US1,200 rebate in the US. See:-
It seems that the 645D would be replaced very soon and Pentax is trying to clear its stock as fast as possible.