Nintendo has a habit of releasing new trailers for Zelda games at the Game Developers Conference (GDC). I expect a new trailer to be released between March 2nd and the 6th.
afaik Nintendo isn't speaking at GDC this year. They do have a booth though. Maybe there'll be a private roundtable or something, but I wouldn't get my hopes up. An "Upcoming 2015 Games" Nintendo Direct is much more likely.