In this minority government, it will take the combined votes of the Bloc Quebecois under Gilles Duceppe, the NDP under Jack Layton, and the Stephane Dion's Liberals to topple the Conservative government of Stephen Harper.

The assumption, based on previous votes, has been that Jack Layton and Gilles Duceppe could be counted on to vote against the government on any confidence motion.  Thus it fell to Stephane Dion to chose the timing of the next election.

We forget that things change.  Time has passed, and an interesting article points out that for Gilles Duceppe and the Bloc Quebecois, a spring election might not be very desirable:

Yes, Liberal Leader Stéphane Dion has announced he will no longer be propping up the government and has told the party faithful to prepare for a 2008 election. Then again, what else is he going to say? He can hardly tell Liberals and the country that as leader of the government-in-waiting he plans to spend the next 12 months propping up the incumbents.

Perhaps he figures it is the Bloc Québécois' turn to do some of the heavy political lifting required to delay an election. Why would the Bloc take over such a role?

Because they may be facing another provincial election in Quebec this spring. If this happens, the separatist forces will want to devote all their efforts to erasing the embarrassing results from last March's Quebec election, when the Parti Québécois came a dismal third behind Mario Dumont's Action Democratique in a stunning result that saw Jean Charest's Liberals narrowly form a minority government.

The Parti Québécois seems to be faring somewhat better in the polls now that Pauline Marois has replaced the disastrous André Boisclair as leader, and some of the bloom seems to be fading from the rose in terms of the Mr. Dumont's popularity.

This is an interesting take.  Could Stephane Dion have been bluffing about forcing an election in the spring?  Could he have been counting on a Quebec election to distract the Bloc Quebecois and keep them from wanting to fight a federal election too close to a provincial election?

For me, the takeaway from this is to remember that things can change.  Either Jack Layton and Gilles Duceppe can decide that an election is not the right thing for their parties, and keep this government going.  Indeed, the recent recovery of the Liberals puts Jack Layton in a bit of a bind.  Clearly Jack Layton is looking to make major inroads against the Liberals, with the goal of ultimately replacing the Liberals as the official opposition.  That's not likely in one election cycle, but for it to happen at all, the NDP has to make a powerful showing against the Liberals.  If the NDP finishes in its traditional third place with 15% of the vote despite Stephane Dion's weakness as Liberal leader, then the NDP might suffer an existential crisis.

So Jack Layton wants to take on the Liberals when they are weak.  But when the Liberals are weak, Stephane Dion will abstain from votes and avoid an election.  When the Liberals are stronger, Stephane Dion is more likely to force an election, but then the NDP would likely fail to make a breakthrough.  Jack Layton also has the power to have the NDP abstain and keep parliament running if he feels the circumstances aren't right for him.

There is a range of polling numbers where the Liberals think they are strong enough to make a run for government.  There is another range of polling numbers where the NDP thinks they are strong enough to make a run against the Liberals.  If those ranges don't overlap, then when will there be an election?

The polls will move up and down, and all three opposition parties will gauge what those numbers mean for their own goals and act accordingly.  We're all fixated on Liberal fortunes, assuming the NDP and Bloc Quebecois are locked in election mode and so are no longer in the calculation. 

That's not the case for the NDP or the Bloc Quebecois.  Having said that, I expect it more likely that the Bloc Quebecois will support the government than the NDP, at least on a broader range of issues.  But regardless, until the conditions are right for all three opposition parties, the government will stand.