Please don't rely on the legacy to "ensure" admission. Remember that legacies typically only get a "boost" if they apply EA/ED. Stanford legacy does provide a boost - last I heard was legacy admit rate around 14%, non-legacy 7%.
Stanford Alumni Magazine from Nov/Dec had a good article about just this in one of their recent magazines. They have interesting graphs showing how Applications to Standford (along with other Ivy's) have doubled in the last 10 years. While the acceptance of alumni is about triple of non-alumni that still isn't really great chances.
I'm don't expect that my son will be willing to jump through all the hoops to attract Standford or an Ivy. That is OK with me, I think fit is really the most important thing is choosing a university. The competition for the top schools in the past 10 years has gotten extremly intense requiring students not only get almost perfect grades/SAT's but load of extra curriculars, service and something unusual that makes them stand out.
