After doing some more research and contacting the MNR regarding the new 2008 zoning in effect in Ontario, here is what I found:
In waters that border Quebec and Ontario, I don't need 2 fishing licenses to fish, I can use either a Quebec or Ontario license.
In waters that border Quebec and Ontario I can pick and choose which rules to follow, i.e. the more lenient ones. For example, I can keep 6 walleye caught in Lake St Francis under Quebec rules, as opposed to 4 under Ontario rules.
When fishing Ontario waters that border 2 zones, I am bound to whatever zone I'm fishing in. However, for transport purposes, I can cross a "stricter" zone. For example, if I decided to keep a 39" inch musky (I don't think I would actually keep one that small) out of the Raisin river in zone 18, I can cross Lake St Francis (zone 20), which has a 40" minimum under Quebec rules, and a new 48" minimum under Ontario rules.
I confirmed all this over the phone with an MNR agent, I hope he knows what he's talking about...
I hope to start ice fishing by next week, I'll keep y'all posted.