Traditionally console manufacturers lose money per console at launch... the exception in current generation is Nintendo's Wii which actually makes them money when they sell one... and Cube had a slight loss at its launch, but it was minor and only very briefly.
Nintendo long ago dumped the lose a tone of money per system sold and hope to make it up on game licensing. Which is why, even with disappointing mistakes causing their last console to not achieve its potential (though I don't know how anyone can call 24 Million units a failure) still made the company pleanty of money! Wii is even more so.. and lets not forget about Gameboy and DS as well. From a business perspective Big N knows how to make money.
Doesn't rely on other businesses to carry their loses.
They're practically printing their own money with the DS. Games like the brain ones and Nintendogs have sold millions of DS sets to people who otherwise wouldn't buy a handheld game system. They've sold 35 million, expect another 23 mil in the next year. Even if Nintendo doesn't dominate this generation of consoles they'll still be rolling in cash and in a healthy position for the next generation.