As a postscript, (see previous post) I should say that I think the key point in this election was the moment people began to talk about a Conservative majority.
This scared some NDPers into voting Liberal, but it also scared some Conservative-intenders into voting Liberal, too. They were scared for slightly different reasons, of course, but the root cause was the same. Many NDPers were terribly afraid of a Harper majority because they disagree with his policies so strongly. On the other hand, some Conservative-leaners were also scared of a Harper majority -- either because he's an untested property and a majority was too much of a mandate, or because they really support Liberal policies but were considering the Conservatives as a protest.
I'm not sure what this bodes for the future. On one hand, the Conservatives might have some potential for growth when they become a better-known commodity. On the other hand, we see that the Liberal support is elastic, and grows when it needs to.
Furthermore, there is no indication the Conservatives will be considering a leader change or a policy change, so it's difficult to imagine their support going much higher without a bigger Liberal screw-up, or without finding a new important issue that the Liberals are on the wrong side of.