It means nothing. It's a poll, one of many, that shows the NDP leading the Conservatives as the Cons deal with a month of bad news (F35s, economy, robocalls, you name it).
Some people like to attribute it to the "growth" of higher thinking among the population, the new "movement of independents". It really isn't, folks. I have no idea why people do this based on a single poll. Even if you're referring to the trend, it's three years to the next election! What these polls show now, while supremely interesting to dissect and postulate about what's going on in the here and now, will more than likely not affect the actual campaign in 2015 in any significant way.
Not anymore than this poll did, or this poll did, during their time. Fact of the matter is, truly the only poll that matters is on election day - Alberta should've taught us that. And while polling trends now can paint a very pretty picture, don't count on their reliability even a month from now.
But hey, I'm just a little blogger, who am I to say that the super-pundits are making stuff up out of thin air, right?
I'll do a full post on it when the numbers are released - hopefully Harris-Decima comes out with full regionals this time (apparently they didn't last time because of a small sample, which doesn't make sense to me but OK).