As much as we hate on the College board, it's vital to have standardized testing because it levels the playing field. I mean there are some ridiculously inflated GPAs due to the differences in schools and this only rewards people lucky enough to be in 'easier' schools. If America had a standardized curriculum like A-Levels it might be different but for now I think SATs are necessary.

Edit: There's almost always more opportunity for the wealthier student - struggling at a subject? Get a tutor. Need to beef up your extra-curriculars - don't worry, your private school has dozens, you'll be good at at least one. Spending your summers doing nothing? - don't worry, the school has an internship program with local businesses or research opportunities.

I believe that SATs are the one place that there's closer to equality due to the abundance of free resources.