-allows Dean to be caught on camera as a wanted man. (Which...never really comes into major play again.)
-introduces Agent Hendrickson (Which...other than causing a minor blip in FCB, never really comes into play again.)
I hope those two plot points are picked up again in S3. We'll see.
But one of the most interesting things about this episode to me (that I missed when I watched this the first time, OK, and the second time too) is seeing how attached Dean gets to Ronald. He goes out of his way to say that Ronald isn't crazy or dumb. He just lacks training and focus and knowledge. What happens to Ronald just re-enforces the S2
Ronald: "Chinese been working on 'em for years, and the Russians before that. Part man, part machine, like the Terminator, but the kind that can change itself, make itself look like other people."
Dean: "Like the one from T2?"
Ronald: "Exactly! See, so not just a robot, more of a...a...a Mandroid."
Sam: "A Mandroid?!"
I love that Sam is just...ANNOYED throughout this entire episode. He is just OVER trying to deal with other people. He doesn't hesitate in telling Ronald (for his own good) that there's no such thing as a mandroid.
Sam: "He's not a hunter Dean. He's just a regular guy. If he was to go against this thing, he'd get torn apart."
I think this is when Dean starts to get on Ron's side a little. Later, at the bank, Ronald says no one believes him. Dean makes a point to not only say he believes him, but to share information about who the shapeshifter is. Sam's disgust for Ronald is HYSTERICAL ("Hi Ronald.") but Dean is all about teaching him how things work.
Even though Sam warns Ron to stay out of the lights, he still runs right into them. In an AMAZING scene, we see Sam holler "get down!" but the only actual sound we hear is the gunshot as it hits Ronald. We seen Dean scurry to hide behind a counter (again with no sound) as all we hear is Ronald's body hitting the ground.
Dean expresses sadness that Ronald is dead and makes a point to give Ron props for his tracking skills. I think Dean sees that this could very easily have been him without Sam and without the training he got from his Dad.
In fact, Hendrickson then makes the point that the Winchesters are smart, dangerous and expertly-trained. Ironically (or not so) those are the same characteristics that Ronald lacked and that got him killed.
There is nothing hotter IN THE WORLD than Sam taking down two armed SWAT guys by himself.
OK, so, at the end...Dean kills the shifter and we see him kneeling by her bloody body as a SWAT guy walks up on him and he looks panicked. There's SWAT everywhere, no way for the boys to escape. But we as soon as we find out there are two SWAT guys stripped and handcuffed in a closet, "Renegade" starts playing as we see two other SWAT guys running in slow-mo outside the building, into the parking garage and right up to the Impala.
This is just...an iconic music moment. SPN always marries music to its storyline really well, but this is one of the best examples.
The guys pull off their helmets and just...breathe for a sec inside the car. As Dean freaks "we are so screwed," we hear Styx sing from the soundtrack:
The jig is up, the news is out
They finally found me
The renegade who had it made
Retrieved for a bounty
Never more to go astray
The judge'll have revenge today
On the wanted man
Back when Nightshifter first aired, I also did a fairly interesting (to me anyway) comparison of the repetitive imagery in Night Shifter vs. Skin and what it might mean. Check that out too, if you're interested.