Smash 4 Outsells Brawl:
Chances:
Let's break down this down, in terms of numbers:
Melee had around 7 million in sales, with 22 million GCs sold world wide. Giving it an attachment rate of around 1/3.
Brawl had around 12 million in sales, with 101 million Wiis world wide. Giving it an attachment rate of around 1/10.
The Wii U is similar to the GC, so I will use that as a guide to how it performs. The similarities include it lacking third party support, lackluster sales in comparison to a rival, and mainly being driven by Nintendo software. The install base will consist of the Nintendo faithful, as such the sales of Smash will be higher per system.
The 3DS is similar to the Wii, so I will use that as a guide for the 3DS versions. The similarities include a large install base, many "casual" fans owning the system, and a large amount of the youth demographic owning the system.
The Wii U Sales are around 6.6 million right now. Based on my (baseless) projections, I think the overall lifetime Wii U sales will be 11 to 13 million.
I'm guessing the Wii U sales will be similar to Melee's sales, so with that attachment rate, it will be around 4 million.
The 3DS sales are around 44 million right now. Based on my (baseless) projections, I think the overall lifetime 3DS sales will be 78-80 million.
I'm guessing the 3DS version sales will have the attachment rate of around 8 to 9 million. For comparison, Mario Kart 7, Nintendo's other best sellingcrossover series, has around 10 million copies sold. The Mario Kart series sold better on the Wii than Smash did (much better), so I think Smash 4 will also be outperformed by Mario Kart 7. Then again, I think both series have legs and could sell much more over the 3DS life time. Smash 4 will probably be a better game than Brawl, and that could also help out sales immensely, as it could give the game lifetime sales legs,
These estimates are lifetime sales. However, you also have to take into account that dual versions might preclude some from buying both versions if the title. But with two versions, there is a fairly good chance certain buyers will only buy one version of the game, who would normally buy the game it was just available for one of the consoles. I think it will come down to whether the game can propel the Wii U sales to new levels. The Mario Kart series, Nintendo's most consistent home console series, hasnt moved the needle enough my opinion, and it had a better chance that Smash. But Smash has a groundswell of support and hype outside of the Nintendo fanbase.
With that said, 3DS sales will probably be solid, and I could very well be underestimating those. I think the combined versions give this a 75% chance.
Want: 100%
I want both systems to succeed.
City Trial Stage:
Chances: 50%
Sakurai loves his own work. And Fire Emblem.
Want: 100%
And I do too.
Unlockable Taunts:
Chances: 99%
Easter Eggs are plentiful, and I can see there being one specific type of unlockable taunt. That is a taunt between two characters. Because there will be characters that will have to be unlocked, technically these would unlockable taunts. But Sakurai hasnt done it before, what would be the change? Well, both KI:U and FE13 use features that could easily replaced Snake's codecs, with the Gods witty dialogue and the support system. Or Snake could just return.
Actually, now that I think about it, Brawl already had unlockable taunts! Snake gets new codecs (smash taunts_ everytime you unlock a new character! These were too awesome to not continue. So I think they will continue in one form or another.
I have a feeling this isnt what you all meant, but Snake's codec are technically taunts, so I'm sticking with that answer.
Want: 100%
Taunts are like my favorite part of fighting games.