Leiter links to a good editorial concerning philanthropy and higher education. The gist of it is that there's no reason to recognize these gifts to elite universities as philanthropy at all. What they are is transfers of wealth among a limited pool of the privileged, noble gestures of making a sacrifice for the sake of one's exclusive club. It's pretty damning stuff, though I should note that the flagship state schools come in for criticism as well. A particularly damning bit of evidence is that at Columbia almost as much is spent on financial aid for students whose families make $100,000+ a year as those in the $20,000-$40,000 range. This is in spite of the fact that Columbia has one of the most enlightened policies concerning financial aid and equality of access among the Ivies and similar institutions.
My addition would be that from a pragmatic perspective, it is quite perverse to claim real philanthropic intent when giving to an institution like Columbia. With tuition and fees being $31,000 a year, it is an extremely expensive proposition to support financial aid. Would students be that much worse off if the money went to Berkeley, Michigan or UNC (in state tuition and fees of $5,000)? As far as helping the least privileged, one wouldn't give to these universities, but ones even further down the totem pole.