Yawn, its pretty obvious that the Wii could have the longest lifespan on the shelf if Nintendo so wanted, except they will probably discontinue it as soon as the new Wii is released as they don't need low cost profitable hardware duplicated as they don't follow the lose money then pray to succeed model of business. This seems to be their typical modus operandus, especially as the new consoles will offer backwards compatibility.
Microsoft on the other hand don't care whether you have an Xbox, Xbox 360 or Xbox Next so long as you're continuing to purchase services from them. For example, if someone buys a console in the year 2009 and uses it strictly as a media centre/download box for the next 12 years paying their $50 a year credit card payment and im sure Microsoft will be extremely happy. So in that respect they can find a use for the console even if games are no longer being released. The ditto aspect of this goes to the new Primetime service which they haven't released yet, all looking at getting the consumer into what is effectively a long term service contract with them.
They don't need to even have games released for their older systems for them to remain somewhat viable as long as they have a decent userbase supporting the system. So is this a better long term plan for a console? Probably! Sony really is backing themselves into a wall here if they think the PS3 will still be a viable games system in 6 years time as most users either don't buy as many games or upgrade to the latest and greatest which is potentially not their system even!
Tease.
