If you were truly concerned about UI design, you wouldn't have turned the dock magnification effect on.
The magnification effect is TERRIBLE UI design and thats probably why Apple keeps it off by default. When you turn it on, your icons are constantly moving around and hence very bad UI.
I had the magnification on to show off the shadows in case people like the first two posters can't see them. Dock magnification is atrocious UI design, actually the dock itself is atrocious. Moving targets, wrong perspectives, not highlighting which application you are currently selecting.. etc.
My simple fix for the dock is to make it Windows 7 like (hides behind a rock). Make it stretch the entirety of the width of the screen, no magnification options. Finder is always hard left of the screen, recyclebin is always hard right. Then you can define much better areas for application and document shortcuts. The one thing I'd like to see in the Dock is some sort of notion that this is the application you've selected. Way too many times I think I'm in Safari, when I'm in Finder with no windows open and I press Cmd K for search and it pops up the connect to server window, which esc doesn't quit I have to cmd W it.
I think the shadows are just fine. The shadow is done with a 3d perspective thus when you raise and bring forward (the action of making larger) the shadow would naturally move back and get smaller. It is not centered because the light is coming from a angle thus this is why you are seeing what you do.
It happens all the time in the real life. I don't shy why it should happen any differently on your computer.
Shadows are cool.
-Zeek
You're obviously not a designer and shadows are not cool. They were cool when I was starting off playing with photoshop.
The multiple light sources totally throws off the shadowing. There is a light source coming from the keyboard into the screen (causing the back shadow), there is a light source coming 60 degrees off the horizontal casting a shadow on the Dock, AND there is another light source from the original icon itself (the 45 degree angle that the Apple UI spec defines for app icons)
The Dock itself casts no shadow.. which makes it odd as well (especially if you have it hiding)
It's just a mess in my opinion, shoddy work.