Both companies have put off projects to develop oil sands in Alberta because oil prices now are too low to make the projects viable. Alberta's once-booming oil sands sector has cooled as every major company has scrapped or delayed some expansion plans as the price of oil has plummeted from its record high last summer.
Industry officials estimate the oil sands in northern Alberta could yield as much as 175 billion barrels of oil, making Canada second only to Saudi Arabia in crude oil reserves[Rob Gillies, "Two Canadian Oil Giants Join in $15.5 Billion Deal," AP via Yahoo News, 2009.03.23].
I'd love to see you all sell your TransCanada shares... but I suspect cooler financial heads will prevail, and TransCanada will keep laying pipe. Other oil reserves will dwindle, oil prices will creep back up, and folks will come a-knockin' for Alberta's messy oil again.
Still, someday, even that oil will run out, or at least won't be economically competitive with South Dakota's windmills and geothermal installations (not to mention a nice fusion plant!). And then it'll be time to turn those Keystone pipelines into underground power luge runs!