I think it has a shot. The series continues to grow in sales with each iteration, people have been begging Nintendo to make super smash brothers for a handheld, and in a few years time the 3DS install base will be much bigger.

Do you think it will sell 20 million?

On the 3DS it could sell 7 million tops.

Depends really if people will buy both the WiiU version and the 3DS version. If just one, I don't see why anyone wouldn't pick the console version.

I could be wrong being that my primary reason could be said about Mario Kart DS but I believe that the main appeal of a game like Super Smash Bros. is local multiplayer with 4 of your friends; and I don't see this translating well to a handheld.

Is there even a for sure a 3DS version coming? I thought a 3DS version was just a maybe if it didn't take away from the Wii-U version. Given that that system is out in a year and I don't plan on seeing a 3DS version unless it's just a SSBB redux.

It won't happen.

That's asking too much from Nintendo.

20 million is a big stretch, but I think it could do about 12-15 mil WW lifetime sales, because it's the first portable Smash ever, we know its going to have online support (and it better be good Nintendo), and I believe it was Iwata that hinted that the Wii U and 3DS versions of Smash may work in tandem somehow.

Plus, you know this is going to be the only Smash game on 3DS, so that'll definitely help its lifetime sales.

Maybe, it depends on timing and what it really offers... Coop part could be like monhun in japan & good online in the west could give it a chance...

How can i know if i don't even know a glimpse of what will be this game?

Anywas my answer is: i will buy the WiiU one.