My friends in other parties will mock the frame, but from the Liberal perspective I think the early "two choices" distinction is spot on. While clearly in dispute, I'm inclined to believe the 2011 election campaign has already begun. Seems a certain inertia is now in play, barring a major concession, a Bloc appeasement, I think we are already in the important pre-writ campaign.
In recent elections, the Liberals have gone to the narrow "us vs them" distinction, to try and siphon off soft support from other parties. The trouble with this strategy, it usually manifested itself in the dying days of a campaign, denoting some desperation. In the lead up to this election, we are seeing a different tract, a central theme, that may yield more practical benefit, just by sheer repetition and voluntary focus.
If you've listened to Ignatieff's end of year interviews, you'll see that the "two choices" frame is effective in several ways. The coalition question is sure to be part of the conversation, Ignatieff uses the two party choice as an excellent counter, a great segue into why voters need to make a clear choice. The response turns the coalition question around into an argument why you need to vote Liberal. Detractors will say it's typical Liberal behaviour, but I see this early, deliberate frame as an important departure. Factor in a government that is clearly in the "majority or bust" frame, and you can see how their posture will actually feed the Liberal narrative.
Again, I believe we are already in the phony war phase of an election campaign. If we enter a campaign with weeks of pre-sell on the clear choice front, it could well benefit the Liberals. The distinctions between the two parties are now there, sell able divergence on direction, so if we can frame it as a this or that, A or B, a real focused choice, then you very well could grab some soft support from elsewhere. That soft support exists, so the idea of targeting it straight away, prior to the unpredictable storyline of a campaign, is sound and very wise strategy IMHO.