Nintendo launched Wii U in end 2012. Sony and Microsoft launched 8 gen in end 2013. 

If Nintendo lauches a new console in 2016 and Sony and Microsoft launch Next Gen in 2020.

I mean one can consider a 2016 Nintendo console a very early 9 gen lauch or a second very late 8th gen console, right?

Would you consider the 2016 Nintendo console an 8th gen console or 9th?

edit: what if they lauch in 2016 and another in 2021 to counterpart a 2020 ps5 and xbox 2 lauch? Then most people would say that Nintendo lauched a 10th gen one year after the competition lauched the nineth? Weird.

WiiU launched in 2012. PS4 and XOne launched in 2013.

If Nintendo launched in 2016, or any other year, it will be Gen 9.

I thought the AMD rumor was that something would be announced in 2016, not launched?
Regardless, it would be considered Gen 9.

If it's a handheld then yes it's 9th gen.
If it's a home console to be released in '16: Nintendo are retarded.

Well its kinda odd, depends on if this gen lasts as long as the 7th and Nintendo have another new console that launches close to PS5/Xbox -358.
I mean look at what Sega did O_0
http://en.wikipedia.org/wiki/List_of_Sega_video_game_consoles

Your years are incorrect. Where the Wii U did release very close to 2013, it was released in 2012. PS4 and Xbox One were released in 2013. However, Nintendo has always gone at LEAST 5 year console lifetime. Which means, they will release a new console at the end of 2017 or begining of 2018. 

Well, I doubt it will be their console but it will be 9th gen

The AMD rumor makes it seem like the device, whatever it may be, will only be announced/unveiled in 2016, not released.

That said, if it releases in 2017 I'd consider it a 9th gen system. Dreamcast released 2 years prior to PS2 and was also included among the 6th gen systems because it was the successor to the Sega Saturn.

the super nintendo, nintendo 64 and gamecube lasted 5 years. More or less from Xmas 91 to Xmas 96, from Xmas 96 to Xmas 01, and from Xmas 01 to Xmas 06.

Probably a new handheld will be released in 2016, and a new home console in 2017.

8.5 gen. I can't see it outperforming the X1 and PS4 by a great enough margin(whilst staying at a resonable price) if they put out a true '9th gen' console so soon. It would be commercial suicide. I really can't see Nintendo putting out a new home console until 2017 anyway.