I don't mind if Apple gets rid of the chrome, but please don't make it white plastic! More for your own good than mine (I'm happy with my 5 GB Pod).
I've had two iPods (my original was just a whole lot defective), and on both the plastic has taken more damage than the chrome. The plastic scrapes and smashes with minor drops. Sure the metal gets smudges, but the all-black carrying case does a great job of hiding that.
From what I've seen, Apple could be taking a step backwards. The Think Secret rendering only gives you an idea of the form, not the overall look. The new iPods could have an innovative new design to them. We'll have to wait and see.
As for the buttons moving, I think it detracts from the iPod's cool look. I could see the possible benefits of such a change with the touch sensitve scrollwheel models, but it really does look better the way it is now.
Then again, we don't know what this will really look like, so it's hard to say anything definate about the design... yet.