Election possibilities
Anyways here are the possibilities for each party from the best and worse case scenario
Conservatives
Best case scenario: 160 seats - The Tories run a very strong campaign from now until the end and more importantly are able to allay fears with the 3-5% who are swinging back and forth between the Tories and other parties that a Tory majority is not something they need to fear. Also, voter turnout is low and since those over 50 tend to have the highest turnout and are also the group the Tories are strongest amongst, they do better than expected. This would be done by gaining rather than losing seats in Atlantic Canada, They make a modest recovery in Quebec and end with around 20 seats there. In Ontario they make strong gains in the 905 belt and mid sized cities outside the GTA, therefore picking up 15 seats in Ontario. In the West, they pick up 2-3 seats in Saskatchewan and Manitoba, sweep Alberta, and gain 10 seats in British Columbia, otherwise win most of the seats that when for the Canadian Alliance in 2000, but since the centre and left is far more divided than it was then, they don't need to get the 49% the Alliance got in 2000.
Worse case scenario - 100 seats - The other parties continue their attack on the Tories. This leads to major strategic voting so the split on the centre and the left doesn't materialize, while enough soft Tory supporters decide to move elsewhere so the party only gets 33% (that is only a few points lower than what they have now). In Atlantic Canada, they take a big hit and win between 2-4 seats, in Quebec, they lose rather than gain seats winning only 5-6 seats as the Bloc Quebecois continues their relentless attack on the Tories being out of touch with Quebec and the Tories make another announcement than turns off Quebecers. In Ontario, the NDP and Greens realize their vote is only a vote for the Tories, so they coalesce around the Liberals and knock off the Tories in the ten closest ridings (i.e. St. Catharines, Barrie, Kitchener-Conestoga, Ottawa-Orleans) reducing the Tories to 30 seats in Ontario. In Manitoba and Saskatchewan, the Liberals retake Winnipeg South and Desnethe-Missinippi-Churchill River, while the NDP picks up Saskatoon-Rosetown-Biggar. In Alberta, the NDP scores a stunning upset in Edmonton-Strathcona. While in British Columbia, the centre and left split on a province wide basis, but in each riding there is strategic voting whereby in Liberal/Tory ridings such as Richmond, the NDP and Greens swing over to the Liberals while in NDP/Tory ridings such as Kamloops-Thompson-Cariboo, the Liberals and Greens swing over to the NDP. The Tories end up dropping two seats to 15 seats.
Liberals
Best case scenario - 120 seats - The Liberals continue their uptick as NDP and Greens abandon move over to the Liberals to stop Harper while a few soft Tory votes swing over there way as well as the undecided (which is around 15%) breaks heavily in favour of the Liberals as it has in the past two elections. Dion is also performs surprisingly well in the English debate, while the four leaders do a good job of ripping Harper apart and he is unable to counteract their attacks. The Liberals win over 25 seats in Atlantic Canada. In Quebec, the NDP and Green vote collapse in the greater Montreal area while the Tories arts cuts and law and order platform swings a sizeable chunk of Tory voters over to the Liberals. They end up with 20 seats in Quebec, all in the Greater Montreal area and Outaouis though. In Ontario, the NDP and Green vote collapse while the Tories lose some soft supporters and drop to 32-33% in the province. The Liberals snatch half the ridings they lost in 2006 and get between 60-65 seats in Ontario. In the West, the Liberals pick up Winnipeg South and Desnethe-Missinippi-Churchill River in Saskatchewan/Manitoba, while in British Columbia, they maintain 9 seats (lose West Vancouver-Sunshine Coast-Sea to Sky Country, but win either Fleetwood-Port Kells or Saanich-Gulf Islands).
Worse Case Scenario - 60 seats - Dion makes a major blunder in the debates and both the NDP and Tories make the carbon tax a major issue for the remainder of the campaign. It becomes clear Harper will be re-elected, so the question is who would make a better opposition leader. Dion comes across as looking weak, while Layton as a competent and strong one. In Atlantic Canada, they are unable to capitalize on discomfort with Harper and instead the NDP is the prime beneficiary. The Liberals lose seats here. In Quebec, the NDP makes a strong rebound on the island of Montreal pushing the Liberals to an all time low in seats and votes in La Belle Province. In Ontario, the Liberals are reduced to a Toronto party winning around 35 seats, mostly in the 416 and inner 905 ridings and a smattering of ridings elsewhere in the province such as Ottawa-Vanier and Kingston & the Islands. In Manitoba and Saskatchewan, Ralph Goodale is the lone Liberal left standing and his margin of victory is significantly smaller than the last two elections. In British Columbia they take a big hit and win only 2-3 seats.
Bloc Quebecois
Best case scenario - 60 seats
Gilles Duceppe continues his relentless attack on the Tories and how their out of touch with the priorities of Quebecers. This works in getting the progressive vote to unite behind the Bloc Quebecois. Although the Bloc fails to break their popular vote record of 49%, they do break their seat record of 54 seats taking half the Tory seats and also picking up a few Liberal seats.
Worse Case scenario - 30 seats
Harper's numbers remain steady in British Columbia and in Ontario he is ahead in all the swing ridings that matter, so he spends much of the latter half of the campaign, trying to shore up support in Quebec as this is the only thing standing between him and a majority. Likewise both the Liberals and NDP also see their numbers rise. The Bloc Quebecois still comes in first for votes and seats, but has their worst showing since their founding.
NDP
Best Case Scenario - 55 seats
Jack Layton succeeds in setting an all time record of breaking Ed Broadbent's 1988 record in terms of both popular vote and seats. Add to the fact the NDP vote is fairly concentrated, so even with only 20% of the popular vote, they can win many seats. In Atlantic Canada, he capitalizes on Harper's unpopularity in the region and opposition to the Green Shift. He comes out with 8 seats. In Quebec, he attacks the Liberals as being weak, the Bloc Quebecois as being ineffective and the Tories as too extreme for Quebec. He is able to take advantage of Quebec's more left of centre politics and get in the high teens in votes and pick up 2-4 seats. In Ontario, it becomes clear Harper will win, so Layton is able to convince progressive voters he is a more effective opposition leader pointing to the fact the Liberals abstained on 43 confidence measures, while the NDP has voted against the Tories on every single one. He is also picks up some Green supporters. With gains mainly in Northern Ontario, he wins 18-20 seats, the best showing of the party in Ontario. In Manitoba and Saskatchewan, he is able to convince his provincial counterparts to stump for him and in the case of Manitoba have Gary Doer who is very popular give him a strong endorsement. He comes out with 6 seats here. Picks up Edmonton-Strathcona in Alberta. In British Columbia, he turns to his provincial counterparts who are polling at close to 40% for help. The BC NDP and their leader Carole James make clear that Harper does not in any way shape or form represent what they stand for and that he represents what Campbell was like in his first term all over again. Also, they pick up many Green votes as well as those who vote Liberal federally but NDP provincially. Layton walks out with 12-15 seats in BC.
Worse Case scenario - 20 seats - Despite the strong campaign showing, the fear of a Harper majority is strong enough to scare a large chunk of NDP voters into the Liberal arms. In Atlantic Canada, the two incumbents are re-elected, but nothing else, the NDP loses Outremont to the Liberals in Quebec, while in Ontario drops to 5-7 seats. In Manitoba and Saskatchewan, they win Winnipeg Centre and Winnipeg North, but lose Elmwood-Transcona to the Tories. In British Columbia, they are unable to unite progressives and instead end up losing seats to the Tories, only winning 5 seats.
Green Party
Best case scenario is just to win a seat everywhere, but even if they fail to win a seat, if they get above 10% of the popular vote, this will at least make them be taken more seriously next time around. More importantly the fact they could get 10% under the FTFP system will be a huge breakthrough as this is their best showings in European countries that use some form of proportional representation, not their average showing. On the other hand if they win no seats, have no second place finishes and get less than 7% of the popular vote it will undoubetdly be considered a disappointment.
This means that while a Conservative majority is possible, it is not likely and likwise a Liberal win maybe difficult but not impossible. That being said, time is running out and by next week if the Liberals still have a deficit of more than seven points in the polls they are finished in terms of their chances of winning and likewise if by the Thanksgiving weekend, they are not within 5% of the Tories they are also finished. Due to last minute shifts, as long as the last string of polls place them within 5% of the Tories, they could still pull off an upset.