I glanced through the discussion, maybe I'll read it closer sometime, but over the last few years I've sort of adopted my own philosophy, be it right or wrong.
1. How much resolution is enough is an old debate, and their is no correct "truth". What's true for one isn't true for another. Easy to prove, yet people that don't need the resolution think there is something wrong with those that do. I have hundreds of images taken with less capable sensors that cannot hold up to the print sizes I desire. I have images with the same sensors that could be cropped to an interesting image, but then certainly won't hold up. When I am on a shoot, I rarely know what I'm going to get and whether any image will be worth printing large, but my goal is always to never limit my options later ... so I'll always use the highest resolving system I can, and more often than not stitch to take it further.
2. The discussion of sensors out resolving lenses has been going on since the 1Ds Mark 2, a 16.7mp sensor. The idea is once you out resolve the lens more resolution isn't helpful. but resolution of detail using a bayer sensor array is pretty complex, and considering that detail is made up of blur circles, you have to over sample the data.(I think Eric demonstrated some of this in his replies). And most lenses are better than you would think at this. to me the goal is to resolve whatever image the lens forms on the sensor with enough data that you can reconstruct the image without artifacts or other issues at the size you want to display it. So even if there is some "softness", it's hard to capture that softness accurately. Ctein has some interesting articles about this
here and
here. So until we can get to a point that a sensor can completely out resolve the best lens meaning adding more pixels can't produce an observable difference there isn't a reason not to keep improving as technology allows.
3. I really can't criticize camera makers for improving their products, after all without at least some new product cycles they soon may struggle to stay in business. It's not like you have to buy the new model, but someday the current one will wear out or die, and why not have something that's better. And this isn't something new to digital ... film cameras saw constant improvements to stimulate sales as well.
4. As far as the whole idea that only photographers look at an image up close and you only need to print based on the viewing distance ... not buying that one. While it is true that if the viewing distance is controlled and limited then that can be factored in (although consider that viewing distance maybe close ... I have large panos on the walls of 4 and 5 foot hallways), the idea only photographers view an image up close just isn't true. sure the majority don't. But bottom line, most large images getting printed now don't get observed close because they look bad up close. So why keep getting closer if the image has nothing to offer. Many images won't get looked at up close because the image just isn't appealing enough to the observer to look at period. But a great image may intrigue some to get pulled in, examining small areas to enjoy wonderful textures or shapes, the interplay of colors and details in small things ... maybe the character of a face in a portrait. As a photographer I try hard to make images that appeal to me personally, and while many may think they are rather mundane or non exciting, I don't see the world that way. I see the landscape as beautiful, peaceful, calming, relaxing. And I don't want to limit what an observer of my image that appreciates that quality to be limited in how they can enjoy the image. I don't think photography is different in this regard than any other art ... some pieces will pull some viewers in to examine things closer, the brush strokes, the use of technique and color to create detail ... and sometimes it's a "how in the world did they do that" kind of a thing. Some viewers also look at some photographs with similar thoughts.
So for me resolution is important and I hope makers keep trying to offer better capturing systems. I don't mean ignore other aspects, it's all important, and I"m sure there are tradeoffs, so please improve all the aspects.
I know many also mention the idea that a better camera won't make me a better photographer, and for the most part I completely agree with that, but to be honest I've always thought for skilled photographers to say that on a forum which is visited mostly by skilled photographers is sort of a weird thing to say ... sort of a "duh" statement. I print hundreds of images each week by photographers in my area, and some of them are very very good, and some of their images are fantastic ... and most of them can't make a decent 30x40 print, let alone 40x60 or 90" pano. Ok, maybe the don't "want" to ... or maybe they just say that because they can't. And I know it's often not their fault, I understand budget constraints. but I see most of these arguments as excuses for these limitations, and not a valid reason to continue improving systems. To offer these kind of tools to talented photographers seems only fair. And hopefully some day I can get the quality I'm after from a system half the size of what I haul around now.