How about a Story DLC with additional new stages and game modes? New movesets/costumes for characters?

why? I think there is enough content in Smash

I don't think so. Character DLC could mean pay 2 win. Even if it sucks, it is still a disadventge over anyone who doesn't buy it. Stages? Sure, that's fine. But characters? You would need to learn the strategy, is it heavy or light, hits hard or fast, etc. And the only way to know it, is by buying it.
Besides that, having to test a single character to check how it battles against every other character would make it a hell to develop.

This^^^

We are getting a ton of characters (50+) and many play very very differently unlike other games. Also we have customization for every character specials, Mii fighters which is alot of content there (all those accessories+more).

SSB4 is packed out with content and much more than any fighter with tons of modes and games. 

If we get dlc its fine, but i wouldn't expect it. 

So do I. I don't think it needs DLC. But if they expect us to pay for extra content, there better be a lot of it.

The last thing they should to is make you pay extra for a mode that was in a prior game. Maybe as a bonus if you buy both. Otherwise, that should have been in the original game or shuld be free.

They could make it so you can't play with people who have the DLC.

I see. So I agree with most of your post

for $12?!?

$12/$60 = 0.2

0.2 * 35 characters in SSBB = 7
0.2 * 41 stages in SSBB = 8.2

if you think you anything less than 24 additional characters is a ripoff than you mad.

Nintendo's DLC is much better value than anything everyone else offers so I'm sure Smash Bros' DLC will be great too.