The 4 main ways I see Nintendo making money off of their HARDWARE (not software) are:
1) Consoles themselves. Selling at a profit. It seems that Nintendo is selling near breakeven right now, and if they do a price cut that can make it a loss.
2) Royalties from 3'rd party developers. So yeah... Nintendo can declare war if it wants. If it hates money that is.
3) Perhipherals. Which seems less likely given how so many people already have a Wiimote and the accessories from the Wii generation.
4) Additional serivices. Like XBox Live/PSN premium. I don't know how things like Netflix on the consoles work, but maybe the big 3 are able to monetize that somehow and get a cut?
So 1 and 3 are definetly out, 4 seems iffy. And what's more important is that the main source of revenue (game consoles typically are sold at a loss) is completely being jeopardized.
So, why should Nintendo stay in the consoles market?
