Whats it matter , You havent lost anything, you can still run wow as it was for the same performance and looks & people with better systems have the option to make it look nicer.
So, you reckon that by knocking the slider up one notch should constitute a drop in FPS to unplayable levels? If I can run COD4 just shy of maxed out then adding a few shadows to WOW shouldn't be a machine crippler really, should it?
Just for the record, people with newer systems are experiencing the same thing too, so there's something inherently wrong in the way it's been implented.