For sure that's the drawback of success and being at the top. There is only 1 way to go, that's down. So you are forced into several choices:
1) Reinvent yourself
2) Do the same old thing over and over
3) Evolve
I'll be the last one to say any musician should simply keep putting out the same stuff. Music changes, like the impact of rap on rock and they have become dinosaurs in a way. I respect them for not trying to jump on the trend... like trying to sound like Korn. THAT would have been a real disaster and a joke. Thank goodness they didn't buy Ibanez 7 string guitars for the songs. I better watch the video closer.....
I hope they are in transition and evolving. But I really think they are stagnant at this point. There's a whole 'nother discussion and theory on being young, hungry and living the music vs. being older, rich and doing it when you want to.
Being old has nothing to do with it, other that potentially losing physical capability, like deterixy in playing guitar. I don't see Jimmy Page play the way he used to nor do I expect it from him.
On the other hand, I think Jeff Beck is one of the most respected musicians in the world from a guitar player point of view because he has continually been able to change and still sound "important".
Hey, maybe they put the DVD in for "free" because they felt guilty about suing everyone!