I would bet anything that much of the area is highly contaminated. Wasn't that an issue a few years back when there was talk of a big box/power center along Eastern, between Carlaw and Leslie?
One big issue is traffic. Ever since the Gardiner ended at Carlaw, Carlaw northbound at rush hour is bumper to bumper. Eastern Ave, with people using it to get to increasing development (towns & condos) in the Beaches and Scarborough, is also bad. There's virtually no public transit along these arteries, although a DRL may help with the northbound flow, whenever it is built.
Meanwhile, what happened to this?
http://www.blogto.com/city/2013/05/massive_retail_development_and_hotel_planned_for_old_toronto_film_studios_site/