I'm a SpazioGames user and I can specify more that comment...
In the last weeks we asked the editor (who works for NoE) about that statement and he excluded an add-on (like N64DD) or an HD expansion...he also excluded a new console.
But he specified that the Wii has some possibilities who can be unlocked by an update.
You can trust him, but he's not working on the Zelda project so his informations are not always updated...now he's in Japan for a Nintendo meeting, maybe after his return we'll know more :) (but he can't reveal details, just "ideas" like those which he has just said).