You can probably change the text/icon sizing of Powerbook 540 up and down too, it's still a crappy low res screen by today's standards....
More seriously, you make a somewhat valid point in that Snow Leopard doesn't yet have true resolution independence. But tell me, if say you could have even a 2560-by-1440 15" display that showed all your stuff in exactly the same size/proportions as now - only with better detail/clarity - why wouldn't you want it?
I have never understand why people wouldn't want a higher res display. I understand why people want largeish text and icons for readability, but there is no reason at all nowadays for resolution and text/icon size to be linked, and I think this point is very misunderstood.
My primary reason for wanting higher res displays is to see photo and video work in better detail without having to constantly zoom in and out..... E.g. on my Dell I can play back 1920x1080 1080P HD video in full 1:1 resolution, on my MBP there is simply no way to watch it full-res, I will always be watching a scaled-down copy.