Salt and pepper beard here.
The thing to keep in mind is that the designers of the game are almost always on average older than there player base. Those designers have one of two choices. Either they can design a game which appeals to themselves as older players, or else they can design a game which appeals to people younger than themselves.
The latter seems like the best option, but its not. The best option is to make a game as mature and sophisticated as you can tolerate. That way your player base never out grows the game.
Games which are written down to the percieved maturity level of the fan base always fail in the long run. 'Junior' versions of anything are never as enduring. Lasting children's literature always works at multiple levels, else very quickly the reader reaches a point that they are embarassed by thier former tastes and abandon them. Hense, the problem with music pitched to junior high kids. It's good for a quick sale, but its not a lasting phenomenom unless it grows up in a hurry. Even Harry Potter achieves its success by not only working on several maturity levels, but by growing up with its primary fan base.
I think there would be a temptation to write down to whatever is popular amongst 12 year olds currently. This is a temptation to be avoided IMO. Instead, ideas should be gathered I think from whatever is currently above the 12 year olds heads. RPG's always work on the level of 'killing and taking thier stuff'. That's a universal thrill. But you need more than that to endure.
D&D has been successful because it was an adult game written by adults for adults. Read the 1st edition DMG and you see not just a 30+ year old writer, but a 30+ year old writer whose fondness for military, mythological, and historical esoteria makes him seem even older than that. EGG was a grognard in both the old and new senses of the term write from the time he published the game. You don't out grow military, mythological, and historical esoteria easily. You grow into it and with it. Getting the kids on board is the easy part. Keeping them more than a few years or a few sessions is the hard part. I love the look of anime. But I find I have a hard time retaining my enthusiasm as a I age. So it is with the style of gaming 4e seems to promote.
Naruta? I suspect you out grow that as painfully and easily (and all the more painfully because it is easy) as you outgrow 'Gatchaman', GI Joe, 'Land of the Lost' and all the rest of the stuff I thought was cool as a kid. It might not seem like it at 20 or even 25, but come back and talk when you are 30.
It remains to be seen if the next incarnation of 4e will age as well as The Beatles or Bon Jovi or if it is New Kids on the Block or even New Coke. Anything is possible. Most likely the answer is somewhere in the middle. That's were I'd bet. My objections have never been that it is new. My objections remain the same:
1) I don't appear to be in the target audience.
2) The game doesn't appear to actually solve any of the problems I have.
3) The game doesn't go in the direction I find desirable.
4) It appears as if I'm being forced to buy into someone's homebrew setting. There is nothing wrong with homebrew settings - many are better than some officially supported settings that won't be named and this seems like a good one - but I don't like being forced to by offbeat setting material as part of the core rules.
Those are personal objections. They apply to me. They might not apply to you. If so, have fun.