A Stanford alum made my day the other day, he said my profile was a "perfect fit" for the school based on his classmates... I'm encouraged to say the least...
As for being 31 by the time I matriculate, he said Stanford is going for younger folks, but the students are against it since the older folks are the ones that teaches the class a lot of things. But Stanford wants to make more fiercely loyal alums that will give lots of money, and you gotta start "young" to do that

But there were many over 30's in the class, so he said not to worry too much.
His tips: Talk about yourself. Your personality, your history, who you are. They want you to be BRUTALLY honest but within professional boundaries. They want to know more about who you are than what you did. They look for students with exceptional Emotional Intelligence (EQ).
Hope that helps!