Leica hasen't made their own glass for along time (20+ years). they buy "melts" made to their specification from other manufacturers (Schott, Hoya etc). Unless you have a large production it is not worth while doing it. Cosina has their own glass plant, but only a fraction of the glass they make goes into the CV/Zeiss lenses, The rest goes into the production of high speed surveillance lenses and LCD projection lenses. A fair amount of the optical glass is sold to other camera manufacturers.
In todays world it makes complete sense to "out source" to manufacturing facilities that are specialized. Leica is slowly learning that inventing the wheel every time they start doing something is not economically feasible any more.
Where Leica will be saving money is in the mechanics of the Summarit lens line. They are using a "common" barrel and just shorten or lengthen it to fit the focal length. This is of course what CV did years ago with the 15/21/25/28 mm range and currently is doing with the ZM lens-line.
We should not forget that the mechanics of a lens (glass inciuded) probably account for only 50% of the cost. The rest is assembly and centering of the elements (the centering cost can be as high as 40% of the cost of a premium lens). With a f2.5 this is still important, but with super speed lenses it is critical. You can have the best glass in the world and the most well machined mechanics and a improperly centered lens will only be mediocre at best.
As for where the lenses are made - that is of no significance as long as the QC is up to snuff. Leica was quite late in going to Computer Numerically Controlled machining and this is the standard today. With the proper set up and training of the operator, you can produce glass and helicoils that was impossible before. The tolerances can be held much closer and consistent.
Hand assembly meant that lens elements were sorted in +/- boxes and the elements were then assembled so that a + lens element was matched with a - element to compensate. The tolerances were quite wide (around 5-8% +/-) and todays machines will do much better than that!
Germany might be a high cost production country, but Japan is not much cheaper today. Much of the parts for all camera manufacturers are farmed out, China/Taiwan/Vietnam can outbid any of the high cost producers.
As for differences in Made in Canada and Made in Germany lenses is pure BS! Most of the classic Leica lenses were designed and made in Canada and some of the so called Made in Germany lenses had barrels and/or helicoils made in Germany and the optical cells were shipped from Canada. Why do you think that most of the advertising shots from the 60/70/80's had the Summilux 50/1,4 on the M-body. It was virtually the only M-lens made in Germany for decades!
The Summarit line will offer Leica a set of lenses that, though more expensive than the CV/Zeiss offerings, will allow them some chance of making inroads in the reasonably priced lens offerings. I also trust Leica in that they will not make a lens that would not be comparable to what other makers are offering. They have been in this industry for a long, long time and when they set their mind to it, they can do spectacular things (50/1,4 ASPH/75f2 etc). Now. lets see what they can do in an affordable lens line!
