In addition to a patent for the already announced 25mm f/4 medium format lens, Pentax recently also filed a patent 201263756 in Japan for a APS-C sized 12-24mm f/3.5-4.5 lens (Pentax already has a 12-24mm f/4 lens):
For some reason Pentax US decided to announce the D FA 645 25mm f/4 lens today. This lens has been listed at B&H since February 7th. Here is the full press release:
Just like the first banner, I don’t know much about those images and how reliable this information is. At least we can now clearly see the model name in the top right corner: Pentax K-z.