Panasonic says they'll come out soon with a 25mm F:1.4 lens. This is equivalent to a 50mm lens in the old 35mm format, or a "normal lens".
Many companies in recent years are making fast normal lenses like this. I don't understand it, who has asked for them? They are not all that useful, and I think they only became "normal" because they, on a 35mm camera, are about the easiest focal length to make in good quality and cheaply too. ("Around the length of the diagonal" would actually be 43mm, not 50.)
But what I want is not a normal lens, my first two choices are 1) a slight wide-angle lens for general scene photography, and 2) a portrait lens for people and compressed-perspective photography. Those are really useful lenses. To me, a 50mm-equivalent is sat between two chairs.
...Of course some people have used those lenses to great effect, and if it was the only one I had, it would be a good choice for a universal lens (though I think around 40mm is better). But with a changeable-lens system, I don't see the great need for it, certainly not before anybody makes a good portrait lens (for the M4/3 system for example). Panasonic, I'd much rather have a 45mm F:2.0, please (90mm-equivalent). (There is a 45mm 2.8, but it's expensive and does not have the same background blur a 2.0 would give.)