...it will probably never happen, but I think a "Zero Mission" style Zelda I remake would be cool.
Imagine taking all of the great things about Zelda I (items, enemies, sound effects/music, general overworld and dungeon layout, etc) but redesigning it with Wind Waker style graphics.
Hyrule itself could be rendered in full 3d, OOT style, but they could keep the dungeons primarily the same. More importantly, it would give them an opportunity to enhance the story, and tie up some loose ends in the series.
WW really reminded me of the NES Zelda, so I think it would be fitting.