LOOK! Did You Catch the Symbolism About Dexter on Episode 7.03 "Buck the System"?
Did anyone notice this last night? At the beginning of the episode after Dexter and Deb's arguement about how to control his Dark Passenger, we see that the walls are closing on him because he's under pressure.
At the end of the episode and after Deb says to Dexter that he understands his need and that he should move back to his appartment, the following scene gives us the impression that he's free out of his cage.