No. Not unless Nintendo wants to vastly overshoot the market and doom themselves to irrelevancy again.
The next Wii will incorporate some new technology, but it'll be something that your grandmother can use - just like the Wii's motion control idea.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom