I think there are too many old farts here (!)... myself included.
I have two boys in grade school and they love to film themselves doing skateboard tricks and putting it on Youtube with their friends.
My sons go to their friends houses and edit on Imovie and when they come here, they work on KDEnlive (noneof the other kids use Linux).
The non-Linux using kids have no problem using KDEnlive when they are here.
And KDEnlive is excellent the few times I have used it. Stable as well on KDE4.5.
Maybe the kids know something old farts dont know but when I asked them about KDEnlive here, they say "its like any video editor, they do the same thing."
They dont think about it twice.
Take that how you will but if 9 year olds can use KDEnlive as easily as Imovie, I think we are overthinking this.
I still say video software has to come in two speeds: a full version with the kitchen sink and one version that has a minimialist interface (just like when you go into VLC settings) that features the 10 most used features (which will usually mean the majority of the things you do).
The newbie doesnt get overwhelmed, the advanced user doesnt get dummified apps and the newbie who wants to have more options can with one click of the button, have all the options.
I still sometimes go to the VLC preferences and click the see All options and its freaking scary so I think the two views is great there and should be helpful with video editing.