Original: This has just turned up more or less anonymously on the internet, so take it with a grain of salt. These things can pan out true, but equally they can pan out absolutely fabricated.
A video of the Super Smash Brothers Wii U character select screen showing Rayman as a playable option has emerged online. The original video turned up on this YouTube page, but has since been pulled. Luckily, the internet being the internet caught the video and re-uploaded it. You can see that here:
Rayman is currently owned by Ubisoft, so he won't be able to make a leap to Nintendo without jumping through a few hoops first. On the other hand, he's already in Super Smash Brothers on the Wii U as a trophy, so who knows? I'm leaning towards this being potentially real, but then again, anonymous tips on the internet have a spotty track record. Only time will tell on this one.
Turns out this was a clever hoax by a YouTuber. Check out that story here…