Samm

Like you I was skeptical, as I had a similar setup using spaces (a grid of 9), with some dedicated workspaces and some for collections of apps. Mission control and expose in Lion has all the functionality and use that was present in snow leopard (though admittedly in a straight line rather than a grid), and is in many ways even better. I can move around all my desktops quicker and more efficiently than I could in SL, just had to figure out where some of the different settings were.

As for the discussion of why natural scrolling isn't right for mice scroll wheels, well that relies on the idea that all mice use wheels for scrolling - apple's current standard mouse does not, so is more like a trackpad in that regard.

Why would apple change this long-term standard in direction of scrolling? Because they identified a legacy aspect of computing that they decided no longer fitted current technology and moved to rectify that. They have never been afraid to make such sweeping changes which they believe are necessary. With the increase in touch screen computing now and in the future, it makes sense to have this consistency, and if not change now, then when?