Christa Miller, who plays Jordan, is wife of series creator Bill Lawrence. The footage used as Dr. Cox and Jordan's wedding is actually from Christa and Bill's wedding.
Jordan Sullivan, the ex-wife of Dr. Cox, reveals that his first name is Perry.
The first time "Sacred Heart's" had been mentioned, albeit via narrator J.D.
First appearance of Colonel Doctor (during cold opening when JD is waving his arms) and Snoop Dogg Intern (as JD and Kelso are walking to meet Jordan for first time)
"My bad" is a common Americanism one uses to own up to one's mistake. J.D.'s mistake is sleeping with his mentor's ex-wife.