I will probably come off as a bit of a dick to my Milan friends, but the best advice I can give to someone who goes to Milan for the EXPO, is to discover Turin.
no, really, do it. if you live far away you may not have another chance to see Turin, and you’d miss one of the most beautiful, fascinating and complete italian cities.
Milan is ok for the EXPO and the interiors and the museums and for a lot of modern, shoppingy, modernartsy stuff, but Turin really is THE city you have to see in Northern Italy. provided especially if it’s a sunny, clear day.
also: wine. you have no idea about the wine. and the food. really. you can thank me later.