Usually you can extend a lease. When my lease came up on my 2002 Pontiac, my GM dealer actually bought the car from GM at a lower price than my lese buyout. They released the car to me for one year and made money on the deal.
I'd like to buy a new truck but given the current market, I'm not prepared to take a chance. The auto industry has admitted that they have an over capacity issue and the downturn in the U.S. economy will only make it worse. Expect car lots to be full to capacity. The summer of 2008 is going to produce some wild sales and if the Canadian dollar is anywhere near parity at that time, there will be strong pressure for better deals. As I own my truck, I'm prepared to wait another 6 months or longer.