I don't know...Nintendo still seems to innovate pretty well if you ask me. I don't mean to get into the dreaded console wars but some significant entries in this generation are: Eternal Darkness, Animal Crossing, Metroid (sequel by name, but come'on it's about as far from a 2d platformer as you can get), Smash Bro., 1080 Snowboarding and Mario Party (all from N64, but not decades old franchises like Mario & Zelda), Pikmin, Luigi's Mansion (not spectacular, but nice and innovative).
Their other titles, while familiar in theme are still more often than not abolutely spectacular and don't generally just stick to a hack-job formula. Good examples of these are virtually every Zelda game ever made, Mario Tennis, Mario Golf, Super Mario Brothers.
Anyway, I've already said too much. To make a long story short, Nintendo is still among the most talented game developers in the world. Their downfall was greed (the tight control they have always wanted to have on the manufacturing process of games, leading them to stick to the cartridge format while Sony made the obvious switch to CD).
To be honest, the thing I will miss most about Nintendo (considering that they will continue making games even if they exit the hardware market) is their controllers. They invented the gamepad and Sega copied it. Then they invented an ergonomic gamepad with shoulder buttons. Sega and sony copied it (though Sony arguably improved on it). Then they invented Rumbling gamepads with analog sticks. Sony copied. N64 was the first console with four controller ports. The Gamecube controller is the most comfortable, well designed gamepad on the face of the planet (I have small hands, YMMV). Nintendo has always been supremely interested in the gamer's interface between him/herself and the game. It would be sad to see them go.
edit: I just read over all that. Jeez, I'm a dork. Don't get me wrong, I admit to being a Nintendo fanboy, but I'm also a PS/PS2, Dreamcast and PC fanboy. I mean, if good games can be had on a system I want it. I'm even starting to want an Xbox even though I really hate Microsoft. They are more evil than Walmart. Doublefine Productions is XBox exclusive, though, and claim to have no plans to port to PC so before long I will have to buy an XBox.