The lack of games was a combination of many things... not just Zelda.
New consoles. Yes plural. It takes a couple years for any game at least. So they have people testing game ideas for 3D and the new WiiU controller for years before they launch (which reduces available talent on other game creations and then they start on actual games for each system.
Zelda is one of their staple franchises. It has to be a AAA team with large support to be created. Just like eventual main Super Mario games. Plus with no other 'big' franchise coming up soon, Zelda had to be pushed along to fill the void. I'm betting it was originally planned for early 2011 or xmas 2010, but later pushed back as Nintendo likes to ensure games are polished to perfection first. Had it launched on time, there would be no big issue.







