There is an interesting article in today's Trib (linked below) in which small vendors of high quality and unusual food items cite the expansion of Trader Joe's in the Chicago market for a decline in their business revenues.
Having lived in Manhattan in the early 1990s, I was witness to the "malling" (arrival of chains that pushed out local places)that took place in that city throughout the 1990s. It all started with Starbucks opening down the street from an excellent local coffee house in my neighborhood. Then Borders oushed out the local book vendor. The excellent German diner that I frequented in Yorktown was torn down to build a mega sporting goods store.
All that said, Chicago really has some living gastronomic treasures. The place mentioned in the article "Buy the Ounce" in Wicker Park is one. The article kind of reminds me that, while I do like TRader Joe's, its important to make sure that our local treasures get plenty of business from us too.