This is the fate of successful homebrew Zelda games. Graphics, audio, and characters are all trademarked until at least 2040 (most copyrights, patents, and trademarks only last for 50 years tops before they enter public domain, though Disney pretty much trampled that, so it's not unreasonable to think that Nintendo could as well).
This is why I've been more interested in making a Zelda-like game than making an actual Zelda game. Tried it once with Unity3D, but version control and teamwork don't really work well with that engine. Was gonna take another stab at it with a guy who knew C++ (which despite my hate for it, I was willing to use for the extra teammate) but he quit because I told him that I wanted to have our own wrapper interface for graphics rather than programming in OpenGL or DirectX directly (for portability reasons; it'd be nice to be able to play on PSP or Wii which use SCE and GX graphics api's)