Now I'll start off with my philosophical deference in this subject, this is not a question of qualification... This question comes up quite often especially in debates about american presidents... Bt i don't believe for myself that anyone is "qualified" to lead the fate of millions and arguably billions with their decisions...
So... I would say of the 3 (technically 4) candidates for the prime minister, harper is by far the best fit to lead the nation. He's been prime minister for 5 years, he's kept Canada in a strong position even after a global economic downturn that hit everyone pretty hard and for all his failings he's a politician who isn't perfect.
If not him, interestingly I'd pick Layton over Iggy (who biasedly I'd admit i dislike very much) and i certainly wouldn't pick a traitor of a nation a prime minister (Duceppe).
All in all.
Harper will remain unless there's some major scandal or revelation and in view he hopefully remains minority, while i think Harper should remain prime minister, i don't want to see a conservative majority either.