I have a couple of rather odd viewpoints, and too much time to kill today.
When comparing chemical silver prints to inkjet there are many factors to consider, and several good points have been made.
Cost of material for chemcial prints is fractional to that of inkjet, but equipment costs of inkjet is fractional to that of those that produce chemical prints. Workflow for a large operation dealing with many files from a large variety of photographers is probably better using chemical processes vs. inkjet for a couple of reasons. First, the workflow is very similar to traditional photographic workflow, which was very efficient. Lab software systems such as Kodak's DP2 allow thousands of files to be inspected, tweaked and sent to production equipment by a single operater in a day, similar to video analyzing of days gone by. Throughput of chemical printers far exceeds inkjet, which adds to overall plant efficiency. Material cost of these prints for a large operation is less than 0.20 per 8x10, so margins at these volumes and this efficiency is pretty good.
The quality question is intriguing, since quality is quite sujbective. The fact is chemical prints can be very very good, and in many cases the "extra" quality of an inkjet print just will not be worth the additional cost. It can be challenging to develop the skill to produce really outstanding inkjet prints despite good equipment ... a facilty highly skilled in printing chemical prints may produce a better product than someone who isn't really that good printing on their Epson 9800 or Canon ipf6000.
As far as gamut, to compare a lightjet/Fuji paper gamut to an Epson on Lustre paper is somewhat fair since the two surfaces and the look of the two will be very similar. However, it seems most "fine-art" prints now are being produced on matte based papers, and if you compare those gamuts, you will find far less difference, and indeed will probably find that the Lightjet exceeds the gamut of the inkjet in some areas, especially in darker colors and dMax, while the inkjet wins in the lighter colors, especially yellows and reds. So deciding an inkjet is better based on a gamut you probably won't be using anyway is a little unfair. The fact is both have a very acceptable gamut, and even side by side in most cases you won't see the inkjet "blowing away" the lightjet print.
As far as longevity, another interesting discussion. The chemical print is a little more durable physcially, the inkjet may fade slower (I'm still a little concerned that the inks themselves are fine, but the papers just may not be as archival as the inks - no one seems to test that very well). What are the chances that either print will live long enough to die from fading? While it may be true that an inkjet may take 150 to 200 years to fade vs a chemical print taking maybe 80-100 years to fade, what are the odds that either print will actually survive even 80-100 years? Not very good odds. Obviously those from photgraphers that achieve that "elite" status and are collected, but while many photographers attempt to postion themselves in that realm, very few of them will actually be considered such 100 years from now. So without that special "collectors" care, the odds are most photographs will die from something other than fading. There is just too many things that can happen over the course of a century or so.
