I've already linked to Postmedia's story setting out Brian Topp's first set of democratic reform priorities. But let's take a look at a couple of the proposals in a bit more detail.
To start off, I'm not sure anybody else has pointed out the significance of Topp's plan to "introduce proportionality" into Canada's electoral system through immediate legislation. In contrast, PR proposals at the provincial level have proceeded through an all-too-easily-torqued referendum process first - and even the NDP's federal platform has been limited to "propos(ing) electoral reform" in contrast to measures which would be implemented more quickly. Which means that Topp looks to be offering more than most candidates to PR supporters as part of his leadership push - though we'll have to see what he means by an element of proportionality. [Update: IP advises in comments that Topp has specifically referred to an MMP system.]
Secondly, Topp's intention to proceed simultaneously with Senate abolition has been criticized as unrealistic. And there may be reason for concern that he's packaged it in with his other Parliament Act proposals. But I'll argue that it's nonetheless an important theme for the next NDP leader to take up - regardless of how the odds of achieving abolition look by the fall of 2015.
Remember two crucial points about the Senate as matters currently stand:
1. Stephen Harper's unelected Conservative Senate appointees see themselves as fully entitled to overrule the will of Canada's elected MPs.
2. Stephen Harper's unelected Conservative Senate appointees will have a massive supermajority in the upper chamber at the time of the 2015 election.
As long as both of those points remain true, a push to abolish the Senate might not be all that much more difficult than, say, trying to pass a budget; indeed, it may be a precondition to being able to accomplish much of anything as a government. And what's more, the best means of changing the minds of the Cons' Senate hacks on #1 may be to advance the cause of abolition forcefully enough to convince them that playing nice will help them keep their publicly-funded sinecure as long as possible.
That means that while staying quiet about the Senate might seem like the path of least resistance for now, it could also carry serious consequences for the NDP's ability to govern after the next election. And so whoever wins the leadership would do well to take Topp's cue in recognizing the Senate as an immediate priority in one form or another.