I still don't see what makes these particular homes so special - they are cookie cutter Victorian houses replicated hundreds of times over barely 5 minutes to the north. My preference would be for Yonge and Bloor to be filled up with as many high rises as possible, with strict anti-demolition policies being implemented in the stable residential areas immediately to the north.
Having said that, I'd rather see these homes stay put for the time being. There are enough underused properties and parking lots not only at Yonge and Bloor but in the downtown area in general that tearing down existing buildings is senseless. Once the city is built out, then we can start talking about projects like this. Furthermore, since full build out is likely 20 years away, it would theoretically be a better idea to restore these homes for the time being than just demolish them in order to "preserve" existing surface lots.