6 years minimum! Ideally it should be 7 years to accommodate long software development cycles. Anybody asking for less is asking for a failure ...

I'd rather an overstayed welcome than a lower amount of quality releases and because of the fact that backwards compatibility isn't so common I'd value longer software support ...

7 - 10 unless we see upgrades to the systems or upgraded systems within 7 years, so maybe every 7 years see an upgraded system and the original phased out in 10-13

The Wii U only had a 3 year life cycle which was horrible. There are not any good games coming out for the Wii U this year, effectively making it a dead console.

Five years is a good number.

Four good years. Usually the first year is shit, so that makes it a 5-year minimum.

Whatever is needed to keep a new console at mainstream consumer price and being significantly enough better than the predecessor.

It'll be four years this November. Too bad they basically dropped support over a year ago.

I loved the lifespan of the 7th gen. I'm down for 7-10 years. Always makes the graphical jump that much sweeter if your not a PC gamer too.

I would like a console to last long enough for me to feel like my investment in buying the console was worth it. The PS3 lasted long enough that I ended up with 50+ games. That is probably the best ROI I have ever had with a console, PS1 with the 30 some games coming in at second.

I get where people say they want NX as soon as possible because Wii U is such a failure they want Nintendo to get a replacement out there so success and games and stuff. I personally would probably not be happy that the Wii U only just got released November 2012 and now the NX is coming within a year or so.

I'm hoping the NEO and SCORPIO end up working like I think they should. Where they are just performance boosts mid gen that allows for those that think 7-8 year gens are too long due to the tech becoming too old to get the tech they want.

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8 years. They cost a lot of money and they way I see it developers don't start fully using the hardware until it's been around for 3 years. So we then get 5 years of games that are using the console power at almost full capacity.
5 years is completely unacceptable and I personally think the developers would be pissed off aswell. Some games can take 2-3 years to make so that means a developer only gets to bring out 2 games.
Take Naughty Dog for instance, their only game for the ps4 has been Uncharted 4 as you can't count last of us Remaster and Uncharted collection as they were PS3 games. I'd like to see more of what they can do with the ps4.