Yup, no doubt about it, this is an awesome idea, and the more I think about it, it should happen. I've given the Maple Leafs a bit of a hard time on these boards, but a game between those two teams at Michigan Stadium, or even the Tigers' ballpark, would be amazing. The NHL has alternated between ballparks and football stadiums since the Classic began, so next year's event should be at a football stadium, so the 'Big House' it is. And hold it at night! Prime ice condition (Pittsburgh in 2011 aside, but Michigan's even colder than Western PA on average.)
Now, as to this NBC not wanting Canadian teams on their airwaves, I think this is the rare time they relax that policy (if it even is an official policy.) First off, the Maple Leafs would not really be the attraction here. The attraction is the outdoor atmosphere, in the freezing cold with more than 100,000 crazed hockey fans in attendance. And the attraction is the Detroit Red Wings. It's the Red Wings, that's all NBC really needs. America's most popular team, against an ancient rival. Adding some history and prestige to this particular game only increases the incentive for even the most casual of hockey fans to watch. People in the States at least know who the Maple Leafs are, and all the NHL and NBC would have to do is to produce a video feature or two on the history of the Wings-Leafs rivalry. That's simple enough for the average goober to understand. It's the U.S. vs. Canada (though not really considering the nationalities of the players, but you all get the point.) It's the RED WINGS. If the Red Wings were playing the Coyotes in the desert - literally, out in the middle of the open desert, let's see the NHL pull that off - it would draw a few million or more viewers.
I also think a Boston-Montreal Classic at some point in the not-too-near future at Fenway Park is absolutely a game that could draw large numbers of casual hockey fans everywhere. Do that one in, say, 2018 or so. Chicago-Boston would also be great, btw, but we're talking Canadian teams here. IF, say, this year's Classic had been scheduled to automatically be held between the previous season's Cup finalists, and Boston vs. Vancouver was the match-up, people would watch (they did in the Finals.) Maybe that should be the reward for winning the Cup, the right to hold the next season's Winter Classic. But, what to do if Phoenix wins the Cup? Or Florida? Or a Canadian team? Then that would get tricky, but it's not as though a warm weather outdoor game hasn't been done before. And there's also the option of being the 'home' team in a neutral site game. Either way, Ottawa, Edmonton, Winnipeg, and Calgary will likely never play in the game, absent a superstar the caliber of Wayne Gretzky.
(For the record, I would still love to see a Classic between the Red Wings and Penguins, sometime before Crosby expires for good ...)