Andrew Leach Lays Out The Odds

"We see Northern Gateway as the most vulnerable," Samir Kayande, vice-president at ITG Investments, said during a panel discussion on the Financial Post website this week. "[TransCanada's Corp.'s] Energy East and TMX [Kinder Morgan Inc.'s Trans Mountain] are most likely [with TMX benefiting from having built the loop through Jasper before the opposition to pipelines really built]," said Andrew Leach, associate professor at the University of Alberta, who participated in the discussion.

"Both have [at least partial] existing rights-of-way and so are starting from a better place....

This sounds about right to me.  Note the modifier "at least partial" in front of rights-of-way. Particularly in the case of Trans Mountain, the ultimate odds of the line gong through depend heavily on how partial is partial. At the moment this is impossible to know, but there is some evidence that the line will breach the current right of way in more places than originally advertised.  This means more land to be purchased, expropriated, or otherwise gained-access to so new pipe can be laid.  More landowners to piss off, in other words.  More legal difficulties, more potential blockades, more bad stuff in general if you are betting on the line.