how long do you think the 3DS's life will be?

im guessing around 4-6 years, what do you think?

Probably the length of the DS's lifespan, around 6 years or so. Though I do think there will be different iterations throughout like with the DS... Nintendo has stated that they have no plans to make a redesign at the moment, but it's inevitable, I'd say at the most, we'll see a new iteration of the 3DS within 3 years.

Yeah, 4 to 7 years. 4 being the shortest if it's pushed by the NGP, which I doubt, but it can happen.

The 3DS life will be as long as Nintendo does not release a successor.