I only like one type of game and I have two ratings.
We have Fun and NotFun.
Fun can be found in many games. In Castlevania DS, in Super Mario Bros. 3, in Zone of Enders 2:Second Runner, Psychonauts, and Katamari Damacy.
NotFun can be found in many games too, such as Madden, ET for the Atari, and in that 50 Cent video game.
All of these games are of various rankings by the ESRB rating system, ranging from E - M. I don't see the problem with anyone liking any style of game. If you like GTA and the 'urban mafia' type of genre, then great. If you like whimsical fun magical platformers, just as great. I like having all of the systems because in all of the systems I can find something I like. Sometimes though, it isn't an option and you have to choose. Just because you chose an XBox over a PS2, doesn't necessarily mean it is superior to the other. A 'Kiddy system' like Gamecube had plenty of games I enjoyed. Baten Kaitos, Wind Waker, Luigi's Mansion and isn't it interesting, that neither of those are holding a Mature rating? Just because something does not have a Mature rating by the ESRB does not make it a game for kids only. If I am a teenager, I am not stuck with playing only those games because that's what the rating says.
I am going to buy a game just because it is fun. Mario is still fun for me, because the game I buy is fun. Megaman is fun for me, because the game is fun. Final Fantasy is fun for me, because the game I buy is fun. Madden isn't fun for me, because the game isn't fun. They can't slap any label on that to change it. They can't suddenly slap a label on anything to make it fun. Why did that crappy paintball shooter suck? It had the liscense of the official paintball company/whatever. The reason? It wasn't fun to begin with. Just because you have a 'childish' image with it, it doesn't become lame all of a sudden. Mario is in no way by anyone's definition of 'mature', but yet it still sells really well. How can this be?
Because it is fun.
Wii will be for kids and kids who want to play mario with two hands and a foot. But for the young adluts and older people who have been used to the feel of the PS2, I think I know what they will buy.
Yes, because of course as we all know, it's not like Ubisoft will magically appear and make an FPS involving the Yakuza and you trying to save your wife from deranged Japanese Mafia members, utilizing a gun or anything. I mean, that's simply UNHEARD of.
Oh wait.
You're able to say with a straight face that that type of game are "for kids and kids who want to play mario with two hands and a foot"? Well, shoot me dead, I coulda sworn that type of genre was kinda dark. The sort of dark you would find in something like, oh...Black? And that came out for the PS2 I recall? This is the first game for the Wii that was revealed. I wouldn't really call it to be a "kid-system". If they at least give the that third-party developer option a shot, I have a feeling they will supply the variety you need.
"Mature" has different meanings to different people. What mature means to me is simple, something that is not catagorized as being childish, or something that 5 year old kids can do.
I find Mario and Luigi: Superstar Saga to be one of the best RPGs on my list. It is genuinely funny, it is fun, and it's for a great system. According to you, this RPG is not a mature product. True. The original RPG, which SquareEnix worked on, it was 'childish', because it had Mario in it I presume? So, it's not mature either? Megaman X, a game that uses the same thing as Mario by placing in the same character over and over, is childish in your eyes perhaps? Yet, it involves terrorism and war. But since a five year old and children can play it, this is probably best left avoided?
In closing (and back on topic),
Once E3 comes and passes, opinions certainly can change. If we are really going to get in some discussion of which one might be superior we'll need to see what games they are going to use.
Hell, if we are REALLY going to discuss, we'll need to wait for them to come out and buy them to see.