An adult friend and I saw "The Incredibles" yesterday. No children were in our entourage. Loved it and will see it again.
For me, a large part of the enjoyment was observing the intricacies of the artistry.
American animation still has its place. IMO, the only reason why they are slowly being pushed aside by Japanese anime is because American animated movies and cartoons no longer have the great stories they used to tell. This IMO, is due to Disneys (which dominated the format before anime and is when the idea that cartoons are a 'kids' thing) basically abandoning the format, and what they are pushing on us is crap (you can even argue it's due to liberalism [especially if you look at the themes of the cartoons they now produce [Pocohantas for example]). Pixar might be the exception, but as you know, Pixar is not a part of Disney. And despite what some people say, it isn't because of the animation style. "The Incredibles", with its great story, would've worked whether it was hand drawn or CGI. As for Pixar, once Cars is out, they will leave Disney. Many animators left Disney because of the change of direction there.
Another interesting thing to note, some of the few animated American series I love, are anime influenced. "Teen Titans" (yets, kids show. But an intelligent kids show) has many obvious anime influenced design. Also true for "Totally Spies" (umm...hehe. Yeah, I like this series too. Don't ask why).