Andrew about Season 5

http://insidetv.ew.com/2012/04/06/castle-greys-anatomy-hawaii-five-0-spoilers/

Quote :

As for next season? Creator Andrew Marlowe says fans can expect much of the air to be cleared.
“I think it’s going to be interesting to see the Beckett/Castle relationship next season when we have a lot of the cards on the table, and when they’ve had fundamental confrontations and each of them knows how the other one feels. I think that’s something that gives us a lot of really intense, fun storytelling,” he says.

I've felt for a while that the reason we have not seen the "fun" interactions from earlier seasons between Castle and Beckett this season was that they were keeping things from the other.

Castle could not be his flirty self with Beckett after the swing set conversation nor Beckett with him because to do so could reveal that she knew of his "I Love You" declaration.

With the secrets between them exposed and each being aware of how the other feels, they can no longer hide behind their walls. They are free to be who they really are knowing full well that the other feels the same. In away I see next season returning to the series roots prior to the start of the Demming arc. It was this arc that let them know that there was something between them, and ever since then they have been struggling with how to proceed with the other...