Don't think it's terribly well-known (and the possibility remains it's an elaborate hoax), but when Marvel: Ultimate Alliance was in development, Activision apparently were keen on throwing Link & Samus into the game as bonus characters, sweeten the Nintendo-branded pot. They even went ahead and got the characters running in the game. Didn't work. Nintendo said no, thanks. Bummer. Ah well, this vid's now surfaced, allegedly of the unreleased content, showing Samus in action. On the PS2 version of the game, no less.
[via Go Nintendo]