Valentin Sama (Click here) which has a good track of rumors just wrote that a Panasonic source said that it’s not sure the lens will have a f/2.8 aperture. The aperture will be fast and constant but it may not be f/2.8! I would be tremendously surprised to see that Panasonic did “fool” us. Although I would be happy if they do it in exchange of a constant f/2.5 or f/2.0 aperture
Anyway, as usual take this statements with a grain of salt. But Valentin already good some crazy rumors right in the past and let’s see if he is right that time too!