I think it's a win-win situation for both Canada and the USA. The USA has always wanted to break it's dependance on mid-East crude oil, and Canada has as much oil as Saudi Arabia, only it's in the form of tarsand oil. The reliable source of petroleum will be good for the US manufacturing sector in that factories that produce everything from pesticides to plastics, from carpets to containers and from cosmetics to aviation fuel will have a reliable supply of crude oil feed stock. Canada will benefit by having a reliable and steady customer for it's tar sand oil.
When the XL Pipeline was first proposed, most people thought it was a no-brainer. The US needs petroleum for heat and power, and Canada has lots of it. Also, there's tons of unused refining capacity in Texas. But, Obama got elected running on a "green future" campaign, and that threw a monkey wrench into the machinery of getting that pipeline built. Things may change now.