The previously mentioned Forum poll has its details out, and it included yet more hypothetical Trudeau polling that really doesn't mean anything at all, but is nice to gawk at.
Forum Research (Federal - November 19th, 2012)
Conservative: 33% (+2%) - 145 seats (+23 seats)
Liberal Party: 28% (+1%) - 99 seats (+9 seats)
New Democratic: 28% (-4%) - 85 seats (-34 seats)
Bloc Québécois (QC Only): 22% (+1%) - 8 seats (+2 seats)
Green Party: 4% (=) - 1 seat (=)
A fairly good poll for the Liberals (though, so was the last one), giving us a nice lead versus the NDP - though way too close for comfort. The NDP, despite trailing in Quebec, 29% to the Liberal's 33%, still take a very healthy share of the seats in that province, 33 to the Liberal's 30. Ontario is also a good race, with all three partie in close contention, 34-31-29, Con-Lib-NDP.
But thats not what you wanted to see, is it? Well, sadly for you I'm not at home, so I don't have the nice graphics, but here's the Trudeau numbers:
Forum Research (Federal "Trudeau Polling" - Nov. 19, 2012)
Liberal Party: 39% (=) - 159 seats (+3 seats)
Conservative: 30% (+1%) - 123 seats (+11 seats)
New Democratic: 23% (-1%) - 46 seats (-8 seats)
Bloc Québécois (QC Only): 21% (+1%) - 10 seats (-5 seats)
Changes are, once again, from the last Forum poll in October, which I covered then too. Not a heck of a lot of difference, to be honest, except for BC (which flipped from Liberal to Conservative leading) and the Prairies (Cons go back to 50% domination).
For hypothetical polling, its been remarkably consistent, even amongst different pollsters. I still think its completely useless, simply because Canadians have no idea what to expect from Justin yet (though they might've received a hint, recently). But this "consistency" is either down to people liking the idea of a Trudeau-led Liberal Party, or they're simply projecting their general angst/disappointment in the current options available onto this hypothetical leader. We saw it happen during the rise of Legault's party in Quebec, it can easily happen federally.
Though I must point out, its not just general Canadians... its the NDP who lose the most voters in this case. That speaks volumes about how uninspiring Mulcair's leadership really is.