It depends on how the online is setup. But for all intents and purposes, I'm thinking of just your typical DLC. You just download and pay for it like anything else. There's not a whole lot to say about it.
Sounds good. I'm starting to warm up to the idea of DLC. But I have concerns, you know, about what the DLC actually are.
For me, I think alternate costumes could be good DLC as long as they are actually the costumes the characters actually dressed in past games. For example:
Mario gets Dr. Mario. Wario gets classic Wario Land overalls. Little Mac gets the pink hooded jacket and sweats. Krystal (not that I want her) gets her original Adventures loincloth. Pokemon Trainer gets his original Red/Blue outfit. These are good examples.
Bad examples would be: Ice Climbers get polar bear and penguin costumes. Ness and Lucas get Paula and Kumatora costumes. You know, lame costume ideas like that. And I don't think that alternate costumes are for everyone and that everyone shouldn't have alternate costumes just for the sake of having alternate costumes.
I'm thinking extra parts for the Stage Builder mode would be excellent as DLC. I imagine them as coming together in sets. For example, the Mario set would include the ? Block, the Brick Block, the Warp Pipe, and Music Note Block and so on. The Zelda set would include the traps and fire-breathing statues from Zelda 1 and Beamos and so on. You could even mix it up and create a stage with Mario's ? Blocks and Zelda's fire-breathing statues.
You know what? DLC could be all right with me if they are really unnecessary and optional and are actually Nintendo content and not made-up stuff. So they are just fun little extras like alternate costumes, extra Stage Builder parts, and music. Nothing major like extra characters and extra stages because they should be readily available on the game disc from the beginning and they do affect the gameplay a lot unlike the trivial stuff like alternate costumes and so on.
Still, it would be better if all these stuff were available as unlockables in the game disc from the beginning so we don't need DLC in the first place. That's what Mega Man 10 should have done. Unlock Bass by clearing the game with both Mega Man and Proto Man. Unlock the Endless mode by clearing the game with Bass. But no, we have to pay more for these optional stuff.
Actually, you know what? Maybe we don't really need DLC if they are just unlockables that are readily available on the game disc. So why do we need DLC again? I mean, the only valid reason I can think of why we need DLC is to download a program from Nintendo to fix bugs/glitches in SSB4.