I know TKD has to be modified for MMA but there are a lot of things that are great about the art.
Timing, distance control, counter kicking, feinting, footwork, angles, speed ...
http://www.youtube.com/watch?v=Gvnh8...eature=related
http://www.youtube.com/watch?v=dWbLtNwRrn0&feature=grec_index
http://www.youtube.com/watch?v=sT1mJnHdCqs&feature=player_embedded