well off the topic of definitions and onto questions :p I think what happened with the short life of the 5th gen was the fact that 3D graphics were increasing really fast at that stage and what was on the consoles was getting outdated. The 6th gen is similar.
I think after the initial 2D phase where game play seemed to rule the roost, 3D took over and said "big and beautiful is better" And so a rush to the 6 generation and then the 7th were made to keep up with technology. this is just what I think though, based on my thoughts now, could be totaly off.
this generation I think the video game industry has hit an all time high and no one specific developer is rushing into the next gen or making threats of bringing out an all powerful console designed to thwart the plans of the competition.
It's almost as if all the developers have a secret agreement not to release a new console any time soon. The wii is going to sell for ever! and so nintendo has no need to rush the market to the next gen. And both sony and ms have built powerhouses designed to carry them for quite a few years where as last gen and the gen before that the consoles didnt quite have that lasting processing power that would keep up with gamers wants and needs.
EDIT:
And in adition i think the ability to produce the games on the system also play a factor. The consoles abilities need to reflect the ability of a developer to make a game. we all know how expensive it is to make current gen HD games and that cost would only increase if the games were being made even better on an even better console. game developement costs need to catch up with the generation before the next can be released. Other wise a new console that can handle graphics 22x this gen would be pointless if devs cant afford to make a game to suport that power.
If at first you don't succeed, you fail
