I just saw your post. Hopefully this is not too late.
The sites on Georgian Bay vary a lot. In the parks you have to camp at actual campsites which generally have enough soil to stake down a tent. However most of the sites on the Bay itself are on crown land, and have no facilities whatsoever. You will generally be setting up your tent directly on 1-billion-year-old rock. You probably want a tent that doesn't need staking to set up, but you will want to tie the tent to some rocks so that it does not fly off in the wind. (I'm speaking from experience.)
Note that Killarney Park is (mostly?) not on the Bay itself. There are some parks on the east shore of the Bay - notably Massassauga.
I did a trip down the southern part of the east shore of the Bay in 2005. There are a few pictures at http://ect.bell-labs.com/who/pfps/trips/2005-06/index.html but no pictures of where we camped. If you want, I can send you one as well as send more information.