Here's a scenario:
Harper spends the first few months of his term cultivating the image of being a moderate by easily getting various non-controversial pieces of legislation passed. He also works to create the impression that he's no Bush toady and that he'll stand up to the Americans by occasionally snarling things similar to what he just said about the arctic. Then budget time rolls around, and in closed door sessions with the opposition parties, he proposes stuff far more extreme than any of them could possibly accept, while refusing to negotiate. Harper emerges from the meetings claiming that all the other parties are engaging in 'obstructionism' or some such thing, and are refusing to permit the enactment of the mandate given to him by Canadians for petty reasons of self-interest. Being a new PM with a quickly established reputation for being pragmatic and reasonable, he is able to control the story and frame the issue as being a conflict over what the others perceive as excessively generous tax cuts. The media buy it, Canadians are annoyed by this, and the opposition all look bad and hysterical. Harper then submits a budget to the house that superficially seems acceptable, but which is actually riddled with radical fine-print measures that are too confusing for most people to understand, and are also guaranteed to get it defeated. It is defeated, and Harper plays the part of the betrayed and deceived victim who was only trying to do what Canadians sent him to Ottawa to do, but was unexpectedly brought down on a confidence vote. A snap election ensues, which the Liberals are unprepared to fight due to their empty coffers and very green new leader (if they even have one yet). Canadians hate being dragged to the polls again so soon, especially because of apparently baseless opposition antics, and reward Harper with a majority.
Shorter version: Harper takes quick advantage of the Liberals' current disarray and deliberately orchestrates a non-confidence vote in order to grab a quick majority. I think this may be a smarter strategy than waiting 2 or 3 years until the reborn Liberals have a stable and confident new leader, more $, and their act generally back together.