I just shot my first soccer game under stadium lights. All I have to say is Holy Sh*T that Flicker function is amazing .... But with the Flicker function and the high ISO I know I chose an awesome upgrade from the 7D.
Here's an example of the Flicker function from a high school football shoot:
Other shots (untouched, straight out of the camera JPGs with various lenses):
This post is a great sales tool for the anti-flicker mode. Canon should buy it from you.