http://www.espnwisconsin.com/common/more.php?m=49&action=blog&r=40&post_id=36721
As it turns out, the Lambeau Leap will be the only post-scoring celebration that will remain grandfathered in as permissible now that the dunk will result in a penalty. When the league enacted its touchdown rules several years ago, those two celebrations, because of their longstanding traditions, were permitted even though they technically violated the rules.