There is usually a lull between a Wednesday debut and the Friday of a holiday weekend, so it was no surprise that "Transformers: Dark of the Moon" dropped to just $21.5 million on Thursday.  After two days of release, the third installment in the robot vs. robot franchise has grossed a very strong $64.7 million.

The previous "Transformers" flick, "Revenge of the Fallen," grossed $29 million on its second day, but that was a much sharper decline after a mammoth $62 million opening day.  It's clear "Dark of the Moon" will not replicate "Revenge's" $400 million gross domestically, but it should finish higher than the first film's $319 million.  Globally is another story.  Paramount is expecting much higher returns overseas.

One optimistic note for the industry on "Dark of the Moon's" performance is that reportedly 60% of all ticket sales have been in 3D or IMAX 3D.  That reverses the recent trend of 3D films unexpectedly dipping below the 50% mark causing alarm across Hollywood's executive ranks.  Clearly, audiences are telling the studios there has to be a reason to see a film in 3D if they are going to spend the extra money for a 3D experience.

Two new films open today to round out the holiday weekend's new offerings, Tom Hanks and Julia Roberts' "Larry Crowne" and the Selena Gomez teen flick "Monte Carlo."

Look for box office updates throughout the Fourth of July weekend on HitFix.