Fair enough, Jono. I too was "reading" your comments as Amin may have interpreted them, about IS versus non-IS lens lens performance. So if I am reading your comments correctly now, Anders is saying that the overall initial design of IS into a lens may create some corner degradation. That may or may not become an issue for some lenses. My thinking is that longer glass will have less of and issue, and that is sort of why I never think much about IS on shorter lenses anyway.
And, as you mention, it may not be significant for other reasons too, such as the fact that I, like many, have to crop the final image somewhat, especially for publication and printing formats, so any issues that could exist at the corners get lopped off anyway. Canon, and Nikon for that matter, have never had stellar corner performance on most of their shorter glass anyway, so how does one separate IS/VR issues from others anyway? (I do understand what Anders is postulating/suggesting, but it seems that any of those issues are already overwhelmed by the glass resolving issues before IS/VR might get designed in to start. Not saying it is O.K., just that most shorter glass, and probably all zooms could benefit from an even more rigorous design and quality build in both Nikon and Canon lines, with or without VR/IS.)
As I commented before, IS/VR can be a great thing in the right setting and under conditions where it works best, but I still do not think it needs to be on all lenses or used all the time.
LJ