I think this and the Variety review are really good news for the success of this film. I'm starting to wonder if the the low end 50 million dollar opening is a bit too low. It would seem as though the stars are aligning for a great opening.
I follow this stuff on a fairly regular basis and I can tell you for a fact that tracking data is far from an exact science. That $50 million estimate was put out several weeks before the films debut. These numbers can vary widely as the release date gets closer.
I think that $50 million may be a little on the low end, but I still would not expect a blow out $100 million opening like some around here are suggesting.
It does seem that showing the film so early was a wise move. Early reviews from major publications such as Variery, The Hollywood Reporter, The London Times and nearly every fanboy website like Ain't it Cool have been almost universally spectacular and have clearly helped the word of mouth/buzz about the film.