In many ways, Corso Italia has already gentrified by quite a bit in the last decade or so. Chain retail/eateries are becoming increasingly prevalent. 7-Eleven, Church's Chicken, McDonald's, Tim Hortons have been joined by Starbucks, Pizzaiolo, and Popeye's. Shoppers Drug Mart is also planning to open and replace around 4 previous buildings/retail units.
Admittedly, the area is not "trendy". But I also don't necessary see the issue or the need for it to be either. The area serves the requirements of nearby residents. Which traditionally have been working class European, and along more recent Latin American immigrant groups. The Italian demographics have been gradually declining for 20-30 years now. Although, the retail landscape remained steadily in tact up until the last 5 years or so. Many of the old-timers are finally retiring their businesses. It's also a societal trend to be shopping for clothing/apparel/shoes at larger centres like the Stockyards, Yorkdale, and Dufferin Mall, etc. Majority of local residents in the side streets nowadays are Portuguese. There's a fair amount of businesses catering to that community but mostly in the restaurant/cafe/bar format. With that said, there are definitely several retail gaps which are continuing with ongoing transitions. Some notable newer stores which have opened include Tea + and Bees are Life Inc.
In terms of the housing stock discussion, it's fairly standard for the West End built form. Ranging from early to mid 1900's era, mixed with common sightings of redevelopment and rebuilds. And honestly just like most of the city, it's becoming increasingly unaffordable. Globe and Mail reported that the average housing price in the Earlscourt-Corso Italia area was $595,620 back in 2015. It's inevitably over $600,000 now, pushing $700,000 depending on specifics.
http://www.theglobeandmail.com/real...es-in-toronto-neighbourhoods/article24060725/