Originally posted by asw66 25mm f2 WR
that lens will be for the 645D and it will be an f/4 lens. It will be interesting if it gives full coverage of the 645 full frame. On the 645D, the new 25mm will be a 19.5mm equivalent in 35mm terms, on full frame 645 a 25mm lens becomes a 15mm equivalent, an extreme focal length but i'm sure it will be useful for architecture.
Personally I would find a 28mm f/2.8 more preferable for the 645D that way it has a 21mm focal length in 35mm terms which I is as wide a focal length as I go, any lenses wider than that are too specialised and don't see much use at all.