I think by now it's very clear there is a lot of intensification that will happen over the next years in Toronto.
Yonge-Eglinton is a central hub like GeneralLee pointed out and I believe it will be considered downtown in the future. Just look at all the new developments popping out daily
http://home.ca/map. I also believe the subway lines play a major role in that and also probably why Yonge-Eglinton real estate prices are the way they are today.