The former radio station headquarters was built in 1892 and 47 St. George is 1900. I don't think its their appearance thats matters, its the fact these once private homes are reminders of St. George Street's character.
Um I really don't think McGuinty is directly involved with the approval of this building. It really just looks like they're trying to merge government offices into one location, rather then the sporadic offices across the city they have now.
Crappy cell-phone image of Bloor, if you look closely you can see Bedford Condo, ROM residence, the Four Seasons, and the Uptown:
http://img99.imageshack.us/img99/9361/tonorth5.jpg