It seems in some ways Lila led Dexter to his demise. The rules of his father was made for Dexter to deal with the harsh reality of having a strong killer instinct won't work in "the real world", everyone wants normal - and Lila believes in the naïve idea that Dexter can become better... for her, to become her puppy (or whatever).

I think they set it up so that the viewers would get some "empathy" for Dexter with the previous two episodes, "Maybe I really can be different", and some Hallelujah "People can change"-bullshit. It was very sweet and very wrong. Dexter is a murderer, except he has (what I believe is) a good motive for his murdering.

However, Lila made him do a lot of mistakes. If they find the body of Dexter's mother's murderer (which now at least 4 recognice from his dept.) they can easily link it to Dexter, that and lots of other things (such as the fact that I doubt Dexter removed the camera footage flawlessly) make me believe that the tightrope is getting ever so uncomfy around his neck.

I see three potential outcomes:

1. Doakes get all the blame. (He is a really irrational character, and a perfect scapegoat)
2. They find out it's Dexter, and he spends a lot of time escaping from the police (good build-up for a Season 3).
3. Lilah, being the weird-ass girl she is loves rejection even more than she loved Dexter's love for her and discovers his true nature and freaks out, and Dexter ends up in an internal mind-struggle whether he can kill her, or risk having his identity revealed (which probably leads to 2... or Lila becomes his alibi, and she gets a leash on him... "If you don't do as I wish I will reveal your secret")).

Damn that Doakes he found the blood samples dammit!!!
Damn Landi he was sooo close busting Dexter in his office!!!
Damn that lila bitch she must die very fast or Dexter will face bigger troubles!!!