The gang's (almost) all here: Kelso, Elliott, Jordan, Ted, a high-fiving Todd, and Zach Braff even appears as a pizza delivery guy. I guess “Cougar Town” really wants to be the crossover-iest of all crossover shows!
But where are Turk, Carla, Dr. Cox, and the Janitor? (Mostly on other currently-running TV shows, I guess.)