See the latest offers here, in US only:-
http://pentaximaging.com/special-offers/
And this is the downloadable claim form:-
http://c758710.r10.cf2.rackcdn.com/files/rebates/1363016044_PENTAX_K5IIsLENS_645DLENS_REWARDS_2013_022613_V2_HR.pdf
So, it seems that Pentax is trying to clean up the last stocks of the 645D and K-5IIs at this moment and that promotion of those FA Limited full frame lenses is obvious. It might hint that replacement of the two models may come shortly and that a new FF body might come, too! Otherwise, they need not to promote those rare FF lenses in their current lineup so keenly! :-D