I'd give him a B letter grade. There are things to disagree with, but I'm agreeing a lot more than disagreeing.
I'd echo the concerns of others that for someone who has a massive majority government he didn't get a heck of a lot done and there's a concern there. One policy announcement that squeaked in before the one year cutoff was the announcement that there'd be a Federal carbon tax imposed on any province that didn't come up with their own system. I don't think this goes nearly far enough, but I understand that the actual necessary solutions don't seem to be politically viable at this time, and I'll take what I can get. If he hadn't announced this I'd be giving him a D and wondering what the hell he's saving all his political capital for.
The other major policy announcement that I strongly agree with is the measures to cool the housing market and limit the government's exposure to the housing market if it failed. Toronto and Vancouver obviously have housing bubbles and this could be incredibly damaging to the country if they burst. Harper/Flaherty started the bubble going in 2005 with policies that relaxed lending, and while rules were tightened over time they never went far enough. I'm pleased that Trudeau/Morneau did the right thing here.
Trudeau's sky high popularity numbers coupled with his relatively shallow amount of first year accomplishments I think says a lot about how incredibly tired Canadians were with Harper's style and how disconnected they were with him. People are happy with Trudeau because he so much better fits the aspirational vision for how Canadians see themselves and their country then Harper ever did. The fact that Trudeau is an international novelty adds to this further. Who doesn't excitedly click on any article about Canada in the NYT? As a small country it's rare that you're talked about.
The pleasant surprise of seeing Trudeau doing things Harper would never do will start to wear off in the second year as it all becomes the norm, not just from Trudeau, but I expect from savvy Conservative politicians as well. If the expectations for the economy remain low he'll be able to coast, but if things decline or people begin getting antsy about the low rate of growth Trudeau will have to deliver on policy to maintain his popularity.