I believe we will see another Nintendo home console. The Wii has provided this possibility being the cash cow it was. And that was only because of the casuals and parents buying into it.
It would be a sad fate just like what happened to Sega, but unlike nintendo, sega had 4 failed home consoles/addons in a row not counting their abysmal handheld sales.
Nintendo still has a lot going for it in the home console market, if only they can sort out thier mistakes made against third party developers over the last 10 years and bring back the traditional control pad.