Zelda hack makes MSNBC news.

Or PMSNBC news, as most people like to call them. IT'S FUNNY, CUZ IT'S A GIRL IN THE GAME AND A GIRL WHO HACKED THE ROM!!! *gets shot*

http://www.nbcnews.com/technology/ingame/princess-zelda-saves-hero-link-hacked-nintendo-game-1C8929795

EDIT: As difficult as it might be to mess with the NES's color palettes, I'd be more intrigued if it were more than a simple re-skin.

The reskin plus text edit is probably child's play compared to the stuff that people have done to Fire Emblem. But yeah, it would be cool if the hacker(s) made the game different in some ways.