I agree that, for film users, the field is already covered with the inexpensive CV15 & 12mm. These are really wide rectilinar lenses that are not used often enough to justify a price tag any greater than what Voightlander is charging. They are a little slow but they are so wide that shutter speeds of 1/15 or less are quite practical. Anyway it would not be worth another 3K for another F stop or so.
However, with a crop camera, the equation shifts substantally. On my R-D1 the 15mm becomes a 22mm. That is a very useful focal length. In fact I use it a lot, both for landscapes and people photos. I Do wish it where faster, but the expense! It is very difficult to design a faster 15mm that also covers a full frame.
My next widest lens is a 21mm f2.8 Kobalux. I would prefer the Leica but not at 6 times the cost. The Kobalux is actually very good, but is nearly unatanable. Cosina, or someone needs to make a similar lens at the less than $1000 price point. There is a market for this both for film and digital users. I had to ply the internet for months in order to find my Kobalux. Thats crazy for a lens that has an effective focal length of 32mm on my Epson and 28mm on the M8. Once the M8 comes out , I would be very suprised if Mr K did not fill the breach.
There is only one big focal length gap that needs to be filled for crop factor digital users. The M8 people will need something around 21mm equivelent to reach the wider end of the spectrum. And it needs to be at least F2.8 Since this translates into 17-18mm, the design becomes extremely difficult if a FF format is also to be supported. As the only real market for the 17mm would be crop users, it doesnt seem to be necessary to design the lens, at a greatly increased price, to satisfy a market that does not exist.
However, no matter how logical, Leica will never design a lens that can not be used on their film cameras. The traditionalist would come out of their trees. It would send a very bad message with regards support of the older format. Plus it would impede further developement of a FF digital camera in the future. So thats not gonna happen.
That leaves third party developers to come up with something. Given the development cost, I don't think will will see anything until the upcoming M8 has been released and proven to be a viable product for third party developers to provide products for.
Meanwhile, Leica will release a wonderful 18mm F2.8 full frame Lens that will retail for about $4000 which I will start saving for but will not be able to afford..........Oh, well
Rex