Twilight Princess was 2006
Skyward Sword was 2011 =5 years
Plus Nintendo has a portable System thats as complex as the Wii was (DS development was easy compared to Wii an 3DS) and making games in HD on WiiU is even harder especially for Nintendo because other studios already know the tricks to make HD games Nintendo had to learn it
So there goes your 3-4 year pattern. 2015 is more likely (even tho sad)
BTW Twilight Princess was first revealed in 2004 (the insane crowd reaction video) Skyward Sword was also first revelaed 2 years before it came out (the link+phi image)
TBH if they need more time to kill the stupid "chose your level" world design and replace it with the conventional "explore a huge connected world" I am happy and they can take as much time as they want. The crippled world in SkywardSword was unbearable....
