Nope. There's 4 of them brother. Go watch the movie again. Believe me, there's 4. I count it. You can even see the extra and they clearly show 4 of them.
However I do take in note what you said that they mesh in together giving the illusion that there are 4 of them, when there are only two....but I'm not to sure - I went over the movie again, I just don't see it.
thanks for the pics above but they are not screen caps. those are production materials made before the design was 100% finalised.
I understand that there were production materials that show four, but they wouldn't mesh right at high speeds(Which is why they eventually went with just two rotors, each with two blades).
I know a guy on the vis effects team. He has shared certain materials with me on the design.
The Bat as finally depicted in the movie has two rotors. Each rotor has two blades and they mesh at a 90degree point from the other blade, synchronised perfectly(So no rotor can go faster than the other. They have to be perfectly in sync or one would destroy the other).
The only thing that changes is the angle of attack. They can pivot in relation to their position on the body.
There is one single definitive scene that proves 100% that there are only two blades per rotor, but you will need a large screen tv and the Blu Ray disc.
When Bruce comes tearing into the cave and lands on the upgraded "double pad", he gets out and walks towards Alfred. In the background, you cam see the blades cycling down, and... Ta-da! There are only two per rotor...
It's the ONLY scene in the movie with the blades shown coming to a halt and as such it's the ONLY canon reference as to the number of blades.
Go and watch the scene! I have a library vide on my PC of all the Bat scenes in extreme HD, and although the "rotors on" scenes make it look like four are spinning, the craft only has two blades per.
I swear.