In an interview with IGN, Masahiro Sakurai told them that tripping has been removed from the upcoming Super Smash Bros. title. For the uninitiated, in Super Smash Bros. Brawl, your character had a small chance to trip and fall while moving, which would render you vulnerable to attacks and unable to react for a brief time. It was terrible. Sakurai mentions that they're trying to strike the balance between the competitive side of Melee and the casual aspect of Brawl with this new game.
He also mentions that they're not planning on releasing DLC for the fighting game. He wants to make both versions "the best and the fullest experience possible." He's not ruling out DLC completely though, as once the game is complete it's something they may or may not take into consideration.
Let us all breathe a sigh of release: *ahh*