blogTO's Derek Flack has a nice photo essay looking at the transformation of Leaside's post-industrial Laird Drive.
Heavy industry has mostly retreated from Toronto in the 21st century, though there remain little pockets around the city where its impact can be witnessed most obviously. The Port Lands fits this description, as does the area around Dupont St. beside the CPR tracks, and most especially Geary Avenue.
These places are so fascinating because unlike so much of the city, they're transitional. Their ties to the past are far more evident than you'll see in a place like West Queen West, where the industrial heritage of the neighbourhood has been effectively wiped clean, and the gentrification process has run its course.
The future has yet to be written in a precious few of Toronto's former industrial zones, and the ultimate character of the streets that comprise them is a process that's playing out before our eyes. You could be forgiven for thinking that you inherit the city in its developed form, but it's always in a state of becoming.
This is perhaps most obvious on a street like Laird Drive in Leaside. There's been enormous change here in the last decade, but there's even more to come as auto garages and remaining industrial tenants slowly give way to redevelopment schemes.