It's true, they do. I'm expecting something truly unique this time though. It better not be the same recycled plot they've used for the past two decades.
I remember being tortured by Nintendo magazines ten years ago with Twilight Princess and it's umpteen supposed release dates, and when it was finally released we essentially got a remake of Ocarina of Time.
Still, there's no reason to build everyone's hopes up and then let them down. It shouldn't have been announced, shown, or promised a 2015 release. Nintendo brought this backlash on themselves.