For the iPod scroller thing, it is an interesting point and now that I think about it, this wasn't really displayed in the keynote.
Yeh there must be a way to do this.
Maybe if you hit the pause button, the volume slider could do double duty and change to a fast forward/rewind slider... or maybe the previous/next track ( |< >| ) buttons do double duty somehow?
On the Apple website and in Jobs' demo, when you're in cover flow mode there's an "i" button on the bottom right corner that's not accounted for... I'm not sure if that would bring you back to the "now playing" screen or what..