Eclipse made 4M more than NM at midnight. Why do you think that is? Probably has something to do with its summer release date. Then, BD1 and BD2 went back to Nov and both of those movies increased by like 3% over Eclipse. Hmmm.
You can't just say that BD1 and BD2 did so well at midnight that it would be illogical to expect it to have done better in the summer. DH2 has shown that a 2D movie can make up to about 36-37M at midnight. And time and time again, we have seen summer tentpoles do ridiculous midnight numbers...TDK, HBP, Eclipse and DH2 were all record breaking midnight films. NM is the only film to break the record outside of the summer season....and it didn't exactly blow past the previous record by all that much (26m vs 22m)