Oh I had a pretty bad one at work for over a year - I hear ya on this.
This definitely looks like a non-uniform lighting issue though and the LED back-light was supposed to fix it. The 15" is small enough that in uniform lighting from a square angle to the screen it should be evenly lit if the back-light is uniform.
I can also tell that it's not a limited viewing angle just by comparing my GF's new SR MBP to my own. Hers has no "hot spot" along any of the edges, so the corners look as bright as the rest. From what I can see, it looks like some of the back-light is escaping from the bottom of the screen, maybe it's as simple as needing to block out the edge a little bit more, and that light casts more light in the area, making the corners darker. If I look DOWN on the panel from above, I can see a line of bright white light on the bottom center edge of the panel. So basically at least on my new MBP, it seems that it's almost "foreground lighting" that is causing the uneven lighting, not an uneven back-light per say.
Does any of this make sense? Difficult to explain.