The latest Iwata Asks regarding networking might have revealed a few things:
1. Random matchmaking online can allow for team battles, but team choices are randomized.
(from Iwata Asks - Part 3: Versus, Co-op, Share)
2. It's possible a more fulfilling stage builder than previously thought might be apparent here. At least based on the commentary Sakurai makes and having moved stage design away from the likes of Big Blue and Poke Floats yet looks to the stage builder as a means to "fill the gap."
(from Iwata Asks - Part 3: Stage Builder)
3. Though it may have been a mistake, Sakurai mentions that players can record entire matches as well as bonuses like Break the Targets to send to friends. When first announced I think it was something like, up to 3 minutes could be recorded and saved, so unless that has changed maybe it was a slip up of sorts.
(from Iwata Asks - Part 3: Super Smash Bros. Spectator)