Two province-wide polls have been conducted in Québec since last week's four debates. Both give 33% to the PQ and 28% to the CAQ. The Liberals trail at 26-27%.
If the popular vote reflects these results, we could be in for a long election night: the PQ would likely be close to the majority threshold - but on which side, we don't know. It might appear surprising that the PQ can achieve a majority with just 33%, but remember that leading the francophone vote is what counts in Québec because there are many similar ridings that "swing" together. The federal NDP, of course, was a big beneficiary of this in 2011.
For the same reason, the CAQ would lose many tight races, and would be at risk of finishing in third place in terms of seats despite beating the Liberals in the popular vote. With current poll numbers, I'd say that the PQ would win 60-65 seats, the Liberals and the CAQ around 30 each, and 1 or 2 for QS.
However, even though these poll numbers give the PQ about twice as many seats as the CAQ, the CAQ still has a real shot at winning government: it trails by only 5%. The CAQ's predecessor tended to be underestimated in the polls. Indeed, in the 2007 election, which bears some resemblance to this one, the ADQ got 30.8% on election night despite being pegged at 25-26% in the last surveys of the campaign. Moreover, although the PQ has actually not been overestimated recently, its support this year relies disproportionately on young voters, who are notoriously unreliable. On the other hand, the CAQ has virtually no get-out-the-vote operation due to its limited means.
To further complicate the situation, many believe that the Liberals will do better than forecast on election night, since many voters may be ashamed to admit voting Liberal due to the anti-Charest hysteria. However, the Liberals are completely out of the picture among francophones, and it will be very difficult for them to get first place. Their only chance is if there's a virtual three-way tie on election night, with all three main parties getting around 40 seats, but that'd require a perfect storm.
In summary, many scenarios are plausible. I'd say that the most likely ones are as follows:
1. PQ minority, CAQ OO
2. PQ majority, Liberal OO
3. PQ minority, Liberal OO
4. CAQ minority, PQ OO
To win a majority, the PQ needs to win lots of tight races against the CAQ, so unless the PQ wins a wafer-thin majority (which, to be sure, could well happen), we will not have a PQ majority with a CAQ OO. Unless Marois commits a huge gaffe, I do not see the CAQ getting a majority, and I also do not see the PQ falling below the Liberals.