If anyone it is companies like Apple/Samsung etc. that Nintendo fears. It wouldn't be much of an effort for them to make controller modules attachable to their upcoming line of tablets.
It's not like Sony and MS were successful with their takes on motion controlling. The Wii was released in 2006. Kinect and PS Move way later and they couldn't take away any oomph off of Wii sales. Apple and Samsung on the other hand have a tight grip on a market and target audience Nintendo is aiming at. You should take a look at the reveal trailer again.
Hunting Season is done...







