I loved Brawl, but the fact that Sakurai actively discouraged competitive play through deliberate mechanical changes was disheartening. Hopefully he can work his way up from Melee's gameplay instead; after playing Kid Icarus Uprising, I have faith in whatever ideas he has to implement.
Agreed, Kid Icarus doesn't let up by allowing players to suddenly trip or something, even players who may be at a slight weapons disadvantage are less of a burden when defeated in Light vs Dark.
He will probably continue to investigate a theme of Risk and Reward as he often does, but any changes to the gameplay I imagine, wouldn't be much different from including Smash Balls and Final Smashes.