I'm still not sold on the fact that she might have been (well I won't say it for those who haven't seen it).
The camera lighting made me kind of think that it was a possible hallucination. I could easily see him falling asleep on the couch while packing those bags and imagining that.
God I hope not. That would be such a cop out, it would make me possibly quit watching the show. Nothing more cheesy than ending a season like that only to start off next year, "All a Dream, la-de-da-de-da, all is well now." Way to Dallasish. As one other person mentioned though, it would be interesting to see her as he sees his father. It would be a good way to openly discuss the conflict he is going to have now in his personality. His Father saying this is what he is (will Dexter now teach his sone the code) and Rita saying he doesn't have to be this. This "Darkness" is what got her killed. I have a feeling Dexter is going to consider this another innocent person he killed. He was definitely responsible. It's going to be interesting to see if he can even stick to the code.
I'm not looking more forward to this show than I am Lost. After that finale last night, wow, I just don't see how any other TV show can compare.