I won't buy the Nintendo 3DS. It just costs way too much, it's Ä100 more expensive than the normal DS. It costs as much as the Nintendo Wii.
I am a fan of Nintendo, but I hope the 3DS will flop like the Virtual Boy. Nintendo just rip their costumers off, because they re-release old games over and over again ("Super Mario All Stars" for Wii, "The Legend of Zelda: Ocarina of Time 3D", "Nintendogs + Cats", "Rayman 3D" etc. etc.). I'm tired of this.
Well, there may be good games for the 3DS launch, and then? I'm sure there won't be good games one or two years after the release.
There are many more disadvantages about the 3DS. The battery service life is only 5 hours, so it is not recommended to use the 3DS for longer journeys. You also can't use the 3D effect in cars or buses, because you have to hold the 3DS completely still to enjoy the 3D effect. So the 3D effect in general is pointless in my opinion, it just increases the price.
I'm sure I'll buy Nintendo's new console, but I'll never buy the 3DS.