From my opinion, everytime I'm watching Psych and I see them together I cannot imagine that It couldnt' have a love story behind.
Am I the only one to think of that ?
It might be possible that the production fired the first actress from the premiere, It just has been used as a way to show the fake Shawn's psych powers then they evaluated that the story would have not any action with a the Lassiter's secret couple.
It's even more possible when I see the second and third episodes, Juliet seems really confident with Shawn, she keeps looking him a pretty good way.
I'm for that following of scenario and I think It's gonna happen for real (I mean in the show)