Dearly Damaged Debra is going to piece it together, I bet. Maybe she already knows, or has always known who Dex is. Also, I see hints that the GF might be willing to be, or become, oblivious or complicit.
I wonder why Dexter wasn't at Rudy's death crime-scene. There were two issues I saw there which would drive a forensics team nuts, assuming they cared enough to look for it: First, the blood drops from the level table followed by the transition to the inverted "drainage". Second, Rudy's body was clothed and there wouldn't be any spatter on the clothes.
There are an awful lot of people who are in a position to link Dexter and Rudy together now. Files lady; Det. Batista, Debra, Doakes, Paul...
He can't kill all of them, can he? Would Dexter's code (Harry's code) permit Dexter to kill to prevent his own capture or unmasking?