Though not quite as definitive as WK seems to think. And Justin's particular suggestion-- a panicked attempt at merger in the runup to the 2015 election if the polls look crappy-- will not end well for anyone, let alone our poor nation. And I am also not yet convinced that the the LPoC can't reclaim enough of Ontario and Que. to form a government on its own.
That said, if Justin is softening to the idea he can convince others to as well. But the merger either has to get started AS SOON AS the LPoC has a new leader in place, or in the aftermath of 2015. The timing doesn't work otherwise (because the merger process will be protracted and miserable and everyone will hate one another for awhile).