Like you guys, very disappointed in the last episode. The season as a whole wasn't really good either. Not as bad as season 3 but definitely far away from season 4 (the best in my opinion).
I was OK with Debra not wanting to know who the killers were, this scene was well done and logical from the characters' personalities standpoint. My problem however was that the whole season was basically made to let you think Debra was going to find out Dexter's true identity by the end of it or at least have big, big doubts about it and yet the finale is the definition of an anti-climax episode... it's almost like she has lesser concerns about Dexter's identity than when the season started!!
The episode in itself was really well done however, but it's definitely a big deception for a finale, especially after all the false leads making us think the finale was going to be huge. It's clearly the worst finale of the entire series, and it's not even close.
I also thought some storylines were concluded too easily (like Quinn is totally cleared just because of the false blood identification... wait, the guy still had his fingerprints all over the van and got the audio and video surveillance equipment at his name!, and also Deb is known as the "barrels case" solver while she didn't find the killers and not even Jordan's body... what the hell?!).
I did like however how Dexter reacted to Lumen's departure and the fact that he feels more alone than ever. It looks like he will be more like "season 1 Dexter" from now on and it's a good thing.
I must admit I have no idea whatsoever of what season 6 is going to look like (I guess the Quinn/Dexter relation may be interesting), but I certainly hope it will be better than season 5, especially by making huge leaps in the principal storyline (Dexter getting caught or at least "busted" by his sister)...
