I get that it has never been done before, but this year has certainly started a precedent for films performing above their normal levels. The Avengers opening with over $200m being a prime example. Skyfall just opened with $88m! A huge jump from the last two bond films.
Then there's The Hunger Games ($152.5m). Until this year, only one film had opened with over $100m during the month of March. Alice in Wonderland set the record in 2010 with $116.1m. The prior record was set in 2007 by 300 ($70.9m).
Now let's look at December. Record holder from 2007, I am Legend ($77.2m). three years later (2010), Avatar just misses the record opening with $77m. Of course, if not for a blizzard that blanketed the east coast with a ton of snow, Avatar would have broke the record and grossed $90m+. Basically, if December holds on par with what happened in March, The Hobbit will definitely create a new record and it could easily open north of $100m.
All I'm saying is that if an adaption of a best-selling novel could defy monthly expectation in March, there is no reason that an adaption of a best-selling novel couldn't defy limitations for the month of December and crack $100m. I went a little lower than my $115m prediction last week and I'm calling for an opening of $108m.