Check out this amazingly well-done documentary on the making of the original Star Fox for SNES.
More than one independent sources apparently claim it's true, and they're starting to win me over.
Looks like there might be a fair number of small changes, making a much harder game than the ROM.
Mr. Brownstone reviews 2002 article about the game.
A TON of news came out recently about Star Fox Zero, and I'm catching up by posting it now. Sorry for the delay.
Discussion of what Retro Studios secret project might be, along with new evidence, and a theory that connects the dots to point towards a Star Fox game.
A new, and very detailed rumor of a Star Fox/Metroid crossover game for Wii U appears on the internet.