The Wii Controllers, Balance Board and new low cost activity trackers could keep them in the hardware and software business if they make them compatible with the various smart TVs, TV boxes and smart phones out there.
Think Wii Fit or other Nintendo games on an Apple TV, Boxee or Steam run. Or using Wii Fit and the Balance board and running though your exercise routines on a phone.
Also a Zelda game that I could play on transit and then move to my TV when I got home would be very much appreciated (Cloud progress sync).
Bigger games could be chunked into smaller segments at lower prices - pay (and download) as you go. Free to play the first few levels - see if you like the game.
One of the things that Nintendo does so very well is write games that people can play together in the same room - it is a shame to see their efforts not reaching more people. My kids have such a blast with their friends on the Wii U - playing old Wii games ;-)