What Happened To Feisty Barbie?

Just finished Scrubs and I figure the writers do some sort of free association comedy because the jokes, as hilarious and well crafted as they are, seem to appear from out of thin air. The show reminds me a little bit of Northern Exposure in the disjointed quirky way you ride through an episode, but when you reflect on what happened in the show you can pick out a theme.
I know there are some nay sayers about Heather Graham, but hey, really sorry, but she is a great actress (who can easily be forgiven for Lost in Space). Her and Sarah Chalke (who's bothering less and less to cover her Canadianess) are a good comedy team. I love the cast, but the writers are my hero's.

Cox has belittled JD in front of JD's students causing JD to lose credibility. Cox agrees to be 'slightly' admonished by JD in front of the students so that JD can regain his credibility.

JD: And another thing, Perry...
Cox: (whispers) The next time you're alone, I'm going to kill you!
JD: (higher pitched, softer whisper) worth it.