Death of a president, new president stepping in and changing a few of the set plans, like chip specs and models, a few system features, and budgets to rush this all out the door? All that could cause a pretty big delay, especially if you want good yields on production.
Complete speculation on my part based on events and rumors, but I'm just playing catch up on all this NX news.
And WiiU has been dead for years to me, so next fall is a wait I'm willing to take, if it means getting it right this time.
Oh, and I forgot all about the new Zelda game. LOL