When AF358 crashed at Toronto, the airport closed down for a few hours. When it was reopened, I heard on ATClive.net that they were allowing planes to land, but warned them that no emergency services would be available if they were to land. Most pilots told ATC that they would have to contact their insurance companies to see if they were able to land.
When the airport was closed, ATC helped planes divert to Ottawa, Buffalo, Hamilton, Winnipeg, Thunder Bay, Montreal, etc. From all accounts, it sounded as though NavCAN was helping pilots to choose the optimal airport to land at based on their destination, current location, and such.
Leahy on Per Seat Costs: "Have you seen the B-2 fly-by at almost US$1bn a copy? It has only 2 seats!"