As everyone knows, digital camera bodies are subject to huge depreciation, and the cost of upgrading cameras every couple of years (if not sooner) can wind up costing thousands of dollars. While the M9 is expensive, if it works as advertised, and is not replaced by a new model for several years, it actually may be cheaper to own than going through the usual Nikon or Canon DSLR upgrades (as I have done several times now). Of course, one can choose not to upgrade one's Nikon, Canon, etc., but that often hard to resist when some major new improvements come along.
I, for one, would love to jump off the upgrade bandwagon for a while, and am wondering if the M9 presents that opportunity more, than say, cameras from the major DSLR manufacturers. It makes sense to me that Leica wanted to introduce a full frame M camera, so the upgrade from the M8 made sense. But now that they have the full frame M9, I wonder how soon they would feel the need to replace it with a more advanced camera. It seems counter intuitive that a lack of innovation and change would be an appealing trait in a camera, but the thought of not being tempted to upgrade for several years is attractive.