Thank you, Sen's Revenge, I will.
As far as the elite universities taking "legacies", I believe (like several other posters) that this practice is largely money driven. To a lesser extent, I believe it is also a matter of the legacy being a "known quantity". It's one more way to winnow down the applicant pool.
There are so many qualified students who apply to the elite universities. If every student who was actually capable of completing a degree were accepted, there simply wouldn't be enough room for everyone.
For example, 29,005 people applied to UVA for this fall. 8,528 were accepted. What about the 71% who weren't offered a spot? I don't feel like looking it up (if it can be found on the Internet anyway), but I'd be hard pressed to believe that most of them weren't capable of spending four productive years in Charlottesville.
With 29,005 applicants, the admissions committee is forced to look beyond grades, activities and standardized test scores for that little lagniappe that makes the student pop off the page. Things like every male relative from 1900 on attending the University...well, that's a big pop!
The college admissions game is, to be honest, a nightmare. It's so arbitrary that any little "in" an applicant has is fair game. That goes for legacy status, skin color, athletic ability or any other thing that makes them stand out.
My two cents; mock away!