Nintendo is killing themselves. Lousy gimmicky machines when they should be focusing on their games. Nintendo is capable of getting back in the game but they refuse to go all in. They clearly dominate the handheld market because they target the younger audience for it. They're capable but unwilling to target the adult audience for whatever reason.
Nintendo has always been a quality brand. Their games are still top notch (most anyway). Their lousy systems have begged companies to make crap shovel ware focused on motion controlled crap. I believe if they would have continued the tradition of putting their seal on the quality titles and not allowing the junk games to see launch they could be doing better. Why I don't buy wii stuff...most of it's crap. Give me a real game.
I dunno...part of the reason Nintendo hasn't gone third party is because Sega went from AAA to Meh almost overnight once the Dreamcast went tits up, sad to say. They don't want to follow in their footsteps...a proverbial man without a country, so to speak.
And funny thing about Nintendo's Seal of Approval--it was all crap. The reason there were so many great games in the NES days is that Nintendo strictly controlled the number of third party games a producer could release--for example, the original Metal Gear was released by 'Ultra', which was a production company made up by Konami, just so they could skirt the six games/publisher/year rule (if I remember the number correctly).
A good read on the early days of Nintendo is the book 'Game Over'. Depending on the print, it will end with the advent of the N64, GameCube, or Wii, but the info about the early and halcyon days of Nintendo is intact and interesting.