If you weigh all the strategic considerations, you can make a strong argument that June is the optimal time for the Liberals to force an election. There's a downside to every scenario, for the Liberals a sense that time is on our side, the more we have to improve fundraising and readiness, the better. It's quite true, it takes time to "rebuild" a party, particularly in areas of the country where the Liberals organization and appeal is currently weak. I'm afraid that sense will lead many to look to the fall "probation" update, as the earliest possible window for forcing an election. I would submit, that what the Liberals may gain on the readiness front could be offset by other factors that could erode the longer we wait.
Ignatieff is riding a pleasant wave, emerging from the budget/coalition debate in a strong position. Ignatieff has positioned himself as a believable PM in waiting, the Liberals have a credibility they haven't had in years, a fickle media generally on side. I see nothing on the near horizon to fundamentally change this dynamic, no bigger tests immediately apparent, than the one's just concluded. Given the primary focus on a cratering economy, which will surely continue through the spring, Ignatieff merely has to stay out of the way, and let events dictate.
I can't remember seeing the Harper team look so unbalanced and in flux. Internal issues, the frame of "strategic genius" now a distant memory, sagging fortunes, principles abandoned, coupled with governing during this economic mess, the Conservatives seem entirely vulnerable. However, to assume this condition is permanent fails to acknowledge the ability of your opponent to adapt. Politics are forever fluid, and with an unknown economic future, there is a risk for the Liberals thinking they can simply bide their time and pounce whenever they choose. If some of the forecasts are correct, the economic numbers may start to flatline, even hints of recovery come the fall, which will surely put some wind in the Conservative sails, a sense that they're coming out the other side. If the Harper government is allowed to hit bottom, and then be able to point to indicators showing the worst is over, that reality is dangerous for the Liberals. Things don't have to be "rosy", they merely have to convey some confidence that it's about to get better. The markets are notorious for being ahead of the economic curve, if there is light piercing the gloom, we could well see some optimism and this will affect the media coverage. Waiting until the fall, is a risky proposition, because nobody really knows where we'll be, so you couple economic uncertainty, with giving your opponent ample time to retool, and you might see an opportunity passed.
June is attractive because you are fairly certain that the economy will be in the "ditch", any campaign rife with poor data, a circumstance which guarantees the government is on the defensive. The Liberals have successfully distanced themselves from the budget, and these "probation" updates provide opportunity to bring the Conservatives down. However, these updates are a double-edged sword, because while they allow control, they also have the capacity to forfeit culpability. Letting the Conservatives live on in March is a given, the budget barely out the door, nobody will expect the Liberals to move, and nobody will really blame them for that decision. Currently, the NDP attacks on the Liberals, this idea of a Con/Lib alliance are feeble and remote, mainstream thought doesn't really entertain the concept, the media largely ignores as nothing more than politics. That said, should the Liberals keep allowing the Conservatives a "pass" on the updates, there is the possibility that these attacks gain steam, because Liberal criticism is eroded with every rubber stamp, on subsequent judgements. March is a given, June is somewhat more intriguing, that is where the narrative can change and we start to "wear" the Conservative budget, or at least we absolve part of the responsibility.
Electorally, the Liberals desperately need to improve their fortunes in British Columbia. Unless the Liberal convention is a historical anomaly, Ignatieff will get a bounce out of the love-in, and it just happens that this event allows a terrific opportunity to showcase the party in a key region. This convention provides a vehicle to sell the Liberal message and Ignatieff's stature will surely rise. The fact it occurs in May, just prior to the June update, means the Liberals could well be riding a wave, some serious momentum.
Parliament isn't in session during the summer, which means if the Liberals did choose to move in June, they can make the argument that this action doesn't impede ability to deal with the economy. An election during the "pause" can be framed as responsible- we can't support the government anymore, we're on the wrong path, a summer election is the best time, if we must have any "uncertainty". I'm not sure that's a powerful argument, but it may help appease a public who wants no part of any election, at anytime for that matter.
I suspect fundraising is on the uptick, we already have some evidence and soundbites to show that things are improving. It will take quite some time for the Liberals to compete with the Conservatives, in terms of money and organization, waiting for that moment seems a far away goal. While the downside of June might be optimal "readiness", one needs to counter-balance that facet with the other issues at play, many of which clearly work to our advantage, many of which might be temporary. When you have your opponent somewhat demoralized, so consumed with merely keeping afloat, coupled with relative "good times" for yourself, it doesn't really get much better than that in politics, and you would be wise to pounce, because the moment may be fleeting.