Here's a website, maintained by a Politics prof at SFU. It summarizes all federal political polls that are released during this campaign. You can also look at province-specific polls of federal politics.
http://www.sfu.ca/~aheard/elections/polls.html
Also, National:
http://www.sfu.ca/~aheard/elections/polls.html#NATIONAL
And, Man/Sask:
http://www.sfu.ca/~aheard/elections/...nal.html#SK-MB
Looks like the Cons peaked early, and are falling back to earth... much like what happened in '04 and '06 (my condolences to a lot of you guys!). One reason for this (in '06 and '08), IMO, is that when people hear or think of the "M" word ("Majority") related to Cons based on their polling numbers, they get scared and plans for strategic voting takes place. Heck, even some who earlier identified as a Con voter may switch - they're comfortable with Harper only in a minority parliament.