30 mil 3DS's sold worldwide and a strong 2013 lineup means the 3DS will be fine.
Nintendo has had to eat a TON of red ink on 3DS hardware to get there, going against their core business model (never sell anything at a loss) and it's still far off the pace set by the 3DS.
The PS3 is doing fine now, but it lost Sony a bunch of money in the process. Nintendo's long term success has hinged on avoiding this kind of product. They did it with the 3DS and have now followed it up again with the Wii U. This is a troubling situation for Nintendo to be in over the next 5 years.
Basically its business as usual. And that's fine by me.
Except that unlike the Gamecube Nintendo actually loses money on both 3DS and Wii U hardware.
They avoided competing with the PS3 and 360 directly because they disagreed with the razors:razor blades model of doing business and knew they couldn't keep pace from a hardware standpoint. When that asymmetrical strategy actually paid off they got drunk on success and walked themselves directly into the very mistake they tried to avoid with the Wii, but now a technological generation behind the competition.
Nintendo likely still treads water over the next 5 years thanks to strong first party sales and a small but dedicated core fanbase, but Nintendo moved very few Gamecubes while still making a healthy profit. They weren't reliant on an economy of scale to bring hardware prices to a profitable point quickly and subsidize hardware losses with rapid software sales. They could make money on every consumer, from the hardcore Nintendo fan to the college kid who only had a GC and Smash Bros. to play with his buddies. Now that later example costs Nintendo money.
Neither the Wii U or 3DS work in their traditional model, and Nintendo's profits are going to contract sharply as a result.