But that for sure isn't true.

The PS2 is very much alive even though the PS3 has been released for two years now!

Lifespan is determined by discontinuation of the console.

I think the other definition is fine, as long as licenced software is still being produced then the manufacturer is still making money off the platform.

Production life of the console isn't necessarily a good definition, the manufacturer could stockpile and continue shipping consoles long after manufacturing ends. I expect Nintendo had already stopped production of the Gamecube before Wii had been released, but they were still shipping them.

If you want to make a list then you'll have to use verifyible dates, obviously launch date is easy, but for end date the only readily available dates are software releases. So then it comes down to either officially licenced games or first party games. This data should be available for all consoles, any of the other definitions I've seen in this thread are too vague.

As for Sony's definition, I take it to mean that it is the length of time they are still producing software for it. Whether there will be a first party PS3 game released in 2015 remains to be seen, but I doubt it.

Sony considers lifespan being from the time the console is launched until the time the last one is manufactured, hence a 10 year life span on PS2 and *heh* PS3.

Well, games aren't cross compatible between it and the N64, and no new ROMs are available for it. This doesn't extend the lifespan of any N64 owner's consoles.

How about when the console and its software stop being advertised on T.V.? Or, arbitrarily, when the console sells less than 250k in a year (apart from it's launch year)?