Over the last five years, especially in big US cities, pharmacies have displaced the corner store. The new pharmacies have junk food, toiletries, make-up, and a few groceries and household items. They're ubiquitous: in New York and San Francisco, there's a Walgreens or CVS or Duane Reed on every block, it seems. Corner stores, family grocerers and newspaper/smoke shops have all but disappeared.
In Toronto, the immigrant-owned small grocer with a display of fresh flowers out front is still ubiquitous, although the pharmacies are getting a foothold in the financial district.
In Waterloo we never had many mom-and-pop grocers (at least in my time there, since the mid-60s); instead, we have stands at the farmer's markets. Diners used to sell candy and cigarettes at the cash, and the only place I know that still does that is The Harmony at King and Central (not cigarettes anymore, of course). Our corner stores were and are of the 7-11 variety, and I wouldn't miss the demise of their magazine racks with porn at the eye level of 11 year-olds.
My main problem with the preponderance of pharmacies is the horror of having the same company dominating every street. Outside they look the same. Inside they look the same. They all carry exactly the same stuff, and there's nothing local or individual about it. You won't find homemade butter tarts or samosas on the counter, as you do at mom-and-pop outfits, or artichokes from the home town of the Italian owners. They don't offer an array of newspapers. Now they don't even have a human being at the checkout.
It is more than nostalgia, I hope, to think that we're losing something here.