A couple of points:
Firstly, I am now 32 (tomorrow!). When I was 18-25, I loved violence in games (it was something new and cool) - played heaps of Doom, Quake, etc. These days I have no interest in that at all. Im completely over 99% of FPS's (including 100% of war games, ultraviolent games, etc). Im interested in original ideas, new gameplay styles, and more. And probably most importantly - social games. Games that interest my wife, her mother, friends and the like.
Secondly - I think it will be great for the industry if the Wii dominates. This INCLUDES Sony & MS. MS have already acknowledged the need to bring new customers into the games industry - Sony seem to be stuck in some form of technology driven, black hole timewarp.
The Wii should be viewed as a "entry" device for gaming - something to get people to START playing games in the first place. Once people buy and own a Wii for a few years, they should have a lot more confidence around other game devices - and potentially this will could lead to a 360 or PS3 purchase.
No matter how hard the others try, the Wii *will* end up being the casual gaming console of choice. The Wii-mote + low purchase price will see to that. This also leaves a significant amount of space (hard-core games) for the other two consoles.
I really think it would have been terrible for the industry if the Wii had failed (it already has not) - in many ways it could have been the death knell for the industry.
I really wish the industry promoted itself better (internally), rather than all this in-fighting that is occurring. They should see themselves competing against other industries - rather than against themselves.