As for the generation lasting another 5 years... I wonder if it will.
The biggest problem facing all three consoles is the lack of ram. Without using more ram to do things differently you gotta wonder if the game companies will bring the needed level of innovation to keep up the consoles another 5 years.
More ram would allow more gameplay innovations with AI and such... then again that feels like it's hardly been utilized on the HD consoles. AI on HD consoles doesn't really seem much more complex then Wii titles... and just doesn't seem anymore complex in most games.