Nintendo isn't a big fan of achievements, so don't expect them to be integrated into a future Nintendo console.
The videogame achievement system made popular by Microsoft on the Xbox 360 and replicated by Sony with the PlayStation 3's trophies has caught on in a pretty big way. However, Nintendo won't be following the leader when it comes to achievements, because the house of Mario sees them as "mythical" and "artificial."
Speaking to Kotaku, Nintendo of America's head of product marketing Bill Trinen (often seen translating for Shigeru Miyamoto) said that Nintendo isn't "opposed to achievements," but that the company still doesn't have any plans to integrate them into a console. He reasoned that achievements are like a command from game designers that "tell you how to play their game in order to achieve some kind of mythical reward."
Trinen believes that Nintendo's games are designed so that players will explore and discover things on their own, sometimes coming upon "unexpected surprises." He finds that this type of game design "really encourages the sense of exploration rather than the sense of 'If I do that, I'm going to get some sort of artificial point or score that's going to make me feel better that I got this.'" Nintendo did include stamps that are similar to achievements in Wii Sports Resort, and an achievement-like reward system in Super Smash Bros. Brawl, but these types of mechanics are likely to be constrained to individual games based on Trinen's comments.
Even though Trinen makes a strong point, it seems like Nintendo is ignoring what has become a major part of the current videogame generation. Certain gamers have been known to seek out, borrow, and rent titles they wouldn't otherwise play just to get a quick boost to their Gamerscore. For these gamers, acquiring achievements and trophies is like a meta-game in itself. At the same time, when I'm awarded an achievement for beating the first level of a game, it makes me feel like an adult being complimented for putting on his pants properly.
Achievements are the most fun when they're surprising, like when you kill 5 enemies with a single explosion in Uncharted 2 and are given a trophy. Nintendo is very good at rewarding its players in ways such as this, so I'm not sure why it wouldn't want to Nintendo-ize the current achievement system and make it something of its own that's less "mythical," and more substantial.