I had to look a little more into the Quebec specific polls to see if there were any trends there, so I recreated the same graph with Quebec polls.
It is hard to make out from the very noisy Bloc and CPC numbers but the Bloc did go below 20%. These are Liaison provincial polls which appear to be consistently the lowest for the Bloc.
There doesn't really seem to be any discernible trend for the Bloc or CPC. Both are fluctuating wildly between pollsters. But the Liberal and the NDP numbers are showing a decline and slight upward trend respectively.
I'll post these Quebec numbers with the national numbers tomorrow and going forward just to keep an eye on it.