The deal was Nintendo would put Rayman in Smash if Ubisoft stopped publishing Wii U games.

That video is pretty convincing proof. Will be interesting to see what his moveset is like.

While his words weren't as strong as I remembered, as of November 2014, Sakurai stated that they were not, and were not planning on working on any paid Smash DLC. Things could obviously change, but this is what I was referring to:

http://www.eventhubs.com/news/2014/nov/19/mewtwo-may-be-only-dlc-character-sakurai-says-nintendo-not-working-any-paid-dlc-super-smash-bros-wii-u3ds-moment/

I'm such a Rayman fan that this increases my hype.

that's a good addition. Now Sora, Bayonetta, and some of the old characters should make it in.

well, im pretty sure its not a fake. looks realy good.

the only thing the video proves is that it is fake.

When a video doesnt show any ACTUAL footage then it has got to be fake... although we all said the same thing with the Duck Hunt Duo leaks.

But honestly I think it is fake, Nintendo doesnt owe Ubisoft anything so they have no reason to promote Rayman.

the current theory with that is that the leaker just has un-released firmware displaying the DLC characters on the CSS.  if you listen around 0:13 in that video you can hear the same sound that plays when you try to select DLC characters you don't have in MK 8.  so if that's true then he wouldn't be able to show gameplay even if he wanted to since he doesn't actually have the characters.

the video has made this almost certainly true imo.  the only step left to seal the deal here is gameplay footage. 

also kind of off-topic but:

this has got to be one of the most mis-quoted developer quotes ever.  Sakurai has said that he makes every Smash title with the mindset that it is the last one.  he's never said anything about the Smash series ending.  and there's no way Nintendo will ever end it, even if Smash 4 is Sakurai's last Smash game (which imo could be likely) they'll just pick someone else up to head it. 

Why wouldn't there be?

Rayman 2 and 3 came out first on Nintendo consoles and then the Rayman Raving Rabbids series, which is exclusive to Nintendo (except one), has been very popular.